"If two friends ask you to judge a dispute, don't accept, because you will lose one friend; on the other hand, if two strangers come with the same request, accept, because you will gain one friend."
It sort of applies, here, as well.
It wasn’t anything serious enough to involve HR (in my eyes anyway), but I spent a solid while annoyed with this response. It took me a solid five years to realize he had made the right overall decision.
He had not played favorites, did not burn any bridges, and caused at worst a mild annoyance to both of us rather than potentially leading one of us to quit.
I have extremely close friends, with whom I have deep, fundamental, disagreements.
I have absolutely no problem, telling people that they are dreaming, if they think they can extort me into taking their side.
"Support" can mean that I won't participate in destructive behavior. I often can't stop others from doing it, but I can make sure I don't get dragged into the cesspool, and be ready with towels and a power washer, when they get out.
If the person you disagrees with becomes your friend then that’s a good sign!