If the seat sub was an instructor/examiner AND suggested busting a limitation that would seem like entrapment. An easter egg in the paperwork is one thing but an instructor actually *telling* you to do something that' going to bust the ride is over the top. That's not the FAA's checking philosophy.

If the sub was just some random dude, another student, reserve, etc then yeah that sucks but you should still know the limitations. It sounds like that.

Still it's more realistic that the other pilot is going to monitor and speak up, that's almost always a good thing but this might be one of those times it's not.