I think it should be clarified that there is a substantial difference between preemptively tagging someone and subsequently removing a tag after further consideration and/or additional evidence coming to light, and tagging someone wrongly and leaving the tag on the account.

In this case, I have not seen any posts from Vod even trying to defend his tag, and I have not seen anyone who supports Vod ask him publicly to reconsider his tag, or to try to defend his tag. Over the years, there have been other similar cases, in which Vod left a questionable tag, and he was never even pressured to defend his tag, his defenders simply said that Vod has left a lot of good ratings in the past, and that they are going to look past the questionable tag. There have also been other situations in which someone received a questionable tag from Vod, handled the situation poorly, and subsequently received additional tags after trolling and/or deciding to rage quit. The later is especially bad for the community because it effectively removes people from the community really for no reason.

To answer your question, I think someone shouldn't be able to get away with many "bad ratings". I don't think this should be a percentage, but rather a raw number, and that number should be very low. I would also view a "bad rating" that is being defended but may not necessarily agree with differently than a "bad rating" in which is not being defended. IMO the later should be viewed much more harshly, and should not be tolerated.