The clique on pub B might talk down on the clique on pub A without any motivation but not B.

Someone that doesn't notice that he is "hated" might also be susceptible to such low key social manipulation to be made believe he is hated.

But ye, as I am not in clique A or B there is a lot of guesswork on my part and I cam't argue against someone else's story. I am just trying to bring up the possibility of bad mouthing.