I would suggest Dr Yeadon may have a personal grudge with Pfizer.
Pfizer had a huge research and drug manufacturing campus just outside Sandwich. So big that the thought that they would ever close it down and leave the area, was unthinkable, but they did think and it did close, with the loss of over 2,000 jobs. This coincides with when Dr Yeadon left Pfizer, I do not know whether the Pfizer redundancy package was generous or not, but I was made redundant into early retirement when my then employer had to massively downsize. We had a very generous redundancy scheme, but never the less some senior managers in particular were very bitter about leaving. One of my managers had to be marched off the premises by security staff with his personal belongings in a black plastic bag and was put on compulsory sick leave because he just wouldn't go.