Searchline. Let us do the hunting whatever expert you need. Please call our free SearchLine today on 0161 834 0017

Journal Detail back to listing

Reflections on Being an Expert Witness
  • Nov 25, 2021
  • Latest Journal

by Dr Peter Wareing, Director, P Wareing Food Safety Ltd

Last year in the Summer issue of The Expert Witness Journal, I wrote about the concept of Food Safety Culture; what it was, and how it could help in reducing the likelihood of food poisoning or illness due to incorrect control of allergens in food. I showed that in many cases where someone was ill due to eating food containing unexpected (not on the label) allergens, Food Safety Culture was either poor or non-existent. This is pertinent now that Natasha’s Law, known as The UK Food Information Amendment, has come into effect on 1st October 2021. It requires businesses to provide full ingredient lists and allergen labelling on foods pre-packaged for direct sale on the premises. The legislation has been introduced to protect allergy sufferers and give them confidence in the food they buy, following the death of Natasha Ednan-Laperouse in 2016. According to the new rules, PPDS (Pre-packed for Direct Sale) food will have to clearly display the following information on the packaging:
• Name of the food.
• Full ingredients list, with allergenic ingredients emphasised (for example in bold, italics or a different colour).

In this article, I will reflect on some of the cases with which I have been involved where an expert opinion was required, and close with two cases in the media, where the expert was called to account. They have covered a range of topics, from suspected food poisoning whilst on holiday, foodborne pathogens being isolated from food ingredients, disputes between equipment manufacturers and food manufacturers, chemical burns whilst working, allergen cross contamination of catering establishments, foreign body contamination, for example. The cases have been civil and criminal, writing a report for prosecution/claimant or defence.

Case 1 Ingredient Contamination
The first case I took highlighted the need to be independent and impartial, a requirement that has cropped up from time to time since then. An ingredient manufacturer supplied a producer of cakes with an ingredient that caused the icing on the cakes to ‘blow’, due to gas production from contaminating yeasts, over the shelf life of the cakes. This was an interesting case which played to my strengths as a food mycologist; someone who investigates yeasts and moulds in foods. In summary, the fault with the cakes lay with both parties; the ingredient was contaminated at the supplier, but the processes at the cake manufacturer allowed this particular high gas producer to build up in the factory, making the problem worse. The group of problematic yeasts were not requested in the ingredient specification from the cake manufacturer, however, practices at the supplier also allowed a build-up in the ingredient.

My report, requested by the ingredient manufacturer, detailed the issues on both sides, including those from ‘my’ side. The ingredient company were very unhappy about this and wanted me to alter it to put the company’s practices in a better light, “Because that’s what we are paying you for.” As it was my first case, I went to the legal team representing the company, who reassured me that my job was to be impartial and fair, and theirs to extract the relevant information to argue the case on behalf of their client. It also bears noting that, at the joint expert meeting, the expert employed by the cake manufacturer tried his hardest to drive me into a corner and agree totally with his argument that the fault lay completely with the ingredient supplier. The settlement was complex, with elements in favour of both sides. I learned some salutary lessons from the case!

Case 2 Dispute between Co-Manufacturers
This was a complex case where a UK company selling supplements had a contract with a US co-manufacturer to produce some of its products. The US company was unable to produce the product to the required specification, and the product also became contaminated. The case was heard there under New York court procedures, but presided over by a UK judge, under UK rules of arbitration, which was a challenge in itself. I was asked to comment. The US company claimed that the process was at fault, and the product could never be made as specified; this despite it being made successfully in UK and European factories.

The experts appointed by the US manufacturer wrote reports that were somewhat biased in favour of the US manufacturer. In total, I wrote three reports for the case: the first giving an opinion on the facts, and commenting on the other expert reports, then two further reports commenting on counter reports, and further counter reports from the other side. All of the reports from those witnesses were somewhat biased and included some elements of calling into question my ability to report on the case. Surprisingly, when the other experts were cross examined and asked to comment on their written opinions of my reports, they agreed they were accurate and well-founded, essentially retracting their views.

Another valuable point learned was the need to be well-prepared; the witnesses of fact for the US company were unable to show that they had command of the evidence, when they were questioned on their statements, denying what they wrote, and employing excessive delaying tactics in answering questions. The case was settled out of court in favour of the UK supplement manufacturer. It was an interesting experience, and perhaps showed the more aggressive nature of experts in the US.

Case 3 Industrial Injury at Work
I was asked to provide an opinion on behalf of a company in which an employee allegedly suffered chemical burns to the mouth and throat from a caustic cleaning product which carried over into the final product. The staff member had taken part in an informal taint taste panel on the soft drink production line. Since two other members of staff did not suffer any burns, it was assumed by the company that it was an erroneous response. Investigation of the incident did show anomalies in the staff member’s account. However, some food safety management procedures related to the incident were either not completely clear, or not being followed correctly or reported properly by staff members. My report showed that there were sufficient grounds for doubt, so that instructing solicitors advised the company to settle out of court.

Case 4 Food Poisoning at a Hotel
In this case, several people became ill after consuming food contaminated with a food poisoning bacterium, Campylobacter, which can occur in poultry. The hotel was served with four charges, three related to the incident, and one to the food safety system that they had in place. After detailed review of the evidence, it was clear that charges 1-3 should be accepted; food poisoning had occurred, and on balance of probability this was caused by the hotel. However, in general the hotel did have a food safety system in place which was implemented and maintained; the problem was that the chef produced this food item as a one off, without a review of the risk assessment for that case. In addition, some of the evidence from the Local Authority hinged on swab samples taken from food and work surfaces. The microorganisms isolated and the timing of the swabs merely showed that surfaces become contaminated when fresh vegetables and salads are prepared; the use of colour coded chopping boards and good cleaning procedures after preparation reduce the risk of cross contamination. Charge 4 was therefore not accepted by the defence, and this was agreed by counsel for the prosecution out of court.

Cases in the Media
Earlier this year, Tesco were fined the largest amount ever for a food business, £7.5 million, for selling out of date food. Cadburys were the previous holder of this distinction, for selling chocolate, which was contaminated with Salmonella, in the 1980’s. The recent case was widely reported in the media, from the BBC and newspapers to the food press, for example The Grocer and Food Safety News.
There are a number of implications for retailers: making sure that all food on display is within the use by date, it is the law, and a simple to follow method to try to ensure food sold is safe. The second is being honest when you get it wrong, it may help working with your local authority. Another implication is that of the honesty and integrity of the expert employed, and the need for that expert to not be persuaded or coerced into a different view to the one that the evidence suggests, for the sake of winning the case.

Judge Qureshi reserved some harsh comments for the expert employed by Tesco in the case, “He even compared the cotton-like mould on grapes to the mould in blue cheese. He is completely at odds with the feeling of disgust that any ordinary member of the public would have on seeing the mould on grapes.” Kate Vickery of Osborne Clarke commented “Tesco presented compelling evidence from a leading microbiologist that the out-of-date food found in the stores in Birmingham was still safe to eat. The Divisional Court disagreed and confirmed that simply selling food past its use-by date was enough to commit the offence.”

The second case was one where Dr Bux, formerly a medical practitioner (now removed from the Medical Register), worked for clients who claimed to have had food poisoning whilst on holiday. Each claim for which he wrote a report was quite small, and so the fraud went undetected for some time; writing some 700 reports between 2016 and 2017, to a value to Dr Bux of over £100,000. The cases involved a conflict of interest because his wife worked at the solicitors which pursued the claims. The judge said that the reports were written “on a boilerplate basis. They were superficial, unanalytical, devoid of any differential diagnoses, and were invariably supportive of the claim."

Online Articles
Natasha's Law - UK Food Labelling Resource - Homepage (
Tesco out-of-date food fine 'a warning' to other chains - BBC News
What does Tesco’s record fine for selling out-of-date food mean for the industry? | Comment & Opinion | The Grocer
Tesco fined £7.5 million for out-of-date food sales | Food Safety News

Dr Peter Wareing, Director, P Wareing Food Safety Ltd.
Dr Peter Wareing has served as an expert witness in civil and criminal trials. Peter’s specialist areas are food safety systems, including HACCP, microbiology and mycology. In his role as Director and Consultant, Peter undertakes troubleshooting audits and investigations for clients, provides guidance on traceability systems and delivers food safety related training. Peter obtained his BSc in Agricultural Science from the University of Leeds and a PhD in Plant Pathology from the University of Hull. Peter is a Fellow of the Institute of Food Science and Technology, a Registered Food Safety Manager and a Professional Food Mentor

Company profile – P Wareing Food Safety Ltd
P Wareing Food Safety Ltd provides expertise and support to a range of clients in the food and drinks industry, ranging from startups, SME’s, through to retailers, larger food manufacturers and local government, both in the UK, Europe and internationally. P Wareing Food Safety Ltd can work in association with food safety and food technology professionals where required, to provide solutions to complex problems.