I find that difficult to believe. It requires two things that are completely out of the ordinary for that to occur:
1. A cop has to lie, not only to ICBC, but probably to his own department
2. An ICBC collision adjuster has to ignore the documentation in front of them, when their job is basically to look at documentation and information from collisions to determine fault and assess the claims.
I deal with ICBC adjusters on a daily basis and I find it difficult to believe that they would "assume" that the other party was at fault because the other guy was a police officer.
Not saying it can't happen, but it sounds like a pretty unusual occurrence.