Believe it or not, I was "corrected" by a leader who wanted me to exert MORE pressure on his R arm...One leader I know who dances milonguero CE hates having the follower's arm around his neck .... Other milonguero leaders I've danced with don't want it on the outside of their shoulder,
I find followers are often given to much misleading information at a milonga. My understanding is that passing an opinion at a milonga is not considered good etiquette, so it does not take a lot to figure the reason for this.
If it's a practica, I'd suggest a conversation about it in a non-blaming, non-critical way.
Especially if it is supervised because I assume there may be two conflicting opinions so this may be helpful.