StuartW wrote:
Obviously I'm playing devil's advocate a bit here
But I'm totally clueless about all the costs stuff, and obviously £10k or whatever is a huge barrier to mounting a defence. And if his regression analysis (or whatever) is a bit rusty, then not much chance of conducting his own defence

The expert report will be in the thousands, and then that expert will need to attend court and give their evidence. Possibly another grand.
This will then need to be presented to the court at trial by a lawyer/barrister specialising in that field. Ten grand in total is not far off.
And if the fella loses, he will be liable for another £700-800 in CPS costs.