I won't take anyone's side here but reading through some of the posts about this Neil fella, I don't recall reading anything that he has done that wouldn't be within the parameters of the law.
At the end of the day, he only needs to suspect that you have a vehicle that doesn't comply with ADR's or emissions and within his power can pull you over. He doesn't have to measure anything either, to send you to Regency.
Based on the little that I've read in regards to his methods (and I know he's become a nemesis to many of you), one complaint alone to his sarg (cause he's only a conny) without any substantiated evidence of ill treatment towards any of you, will end up either in their shredder or bathroom for when they run out of toilet rolls.
A few harsh words from a copper may hurt your feelings but will hardly get him a reprimand, let alone off the force!
30 years ago you would've copped a boot up the ass from him as part of the deal, lol.
If you drive a non compliant vehicle and they eventually catch up with you, smile and cop it on the chin cause it was good while it lasted.