Easy there are loads of independent people who have sat the exams multiple times, who aren’t assessors because they’ve never been invited into the boys club (or not had the right sponsor) any number of them could easily do an assessment as to whether there has been a breach of the exam rules.
CREST is made up of a number of different “groups” - the executive, the assessors and the subcommittees. Out of them the subcommittees are newest and least tainted of all the groups. They would be a good place to start.
The assessors are incredibly tainted for a start a lot of them are NCC or ex-NCC.
There are now over 200 CREST companies with qualified staff, it would be easy to find independent people if CREST wanted to.