I understand your view and yes there are some officials that don’t like Warnock and other managers, there were plenty that didn’t like Ferguson screaming in their ear hole, but it never did them much harm. You can use the fashionable/unfashionable club comparisons, but I think most make decisions based on what they think they have seen, in a split second with honest view rather than a biased one even though they get it wrong. I think it is more a competency issue with refs, some like Stroud seem to try to make it all about them, but I will agree that some refs will have grudges and unconscious bias is something we all battle with, refs will be no different, they are human after all and some managers do cross the line like Warnock with Gavin Ward I think it was at that Swansea game.
That said, you spoke of the alleged Sunderland ST holder, he was one I named above as hoping he is not our ref. In the stands we often do have better views of the action than refs. I think the issue is more to do with the fact they haven’t played the game professionally, so sometimes make mistakes, I can forgive honest mistakes, but what concerns me the most is not so much the mistake, its their frequency and the gravity of the effect. Stroud is the one I struggle the most with for frequency of mistakes. Eltringham, I do question why he is allowed to hold a ST with Sunderland yet referee Boro. I don’t think he is allowed to referee Sunderland though. I have looked back 11 years and could not see a single Sunderland game he has overseen. You say he is Bolton based, well he is refereeing Bolton games, so maybe you got those teams mixed up possibly.