I would say he was. The Kobe clothesline is unquestionable. If you don't call that dirty then you're not judging things fairly. It may have been retaliatory but that's no excuse. That's the only clothesline I've seen in retaliation before. Usually you'll see players hip check or take a shot at a guy when they go up for a dunk or layup. The clothesline wasn't close to a basketball move.
Beyond that, he would flop a lot, more than a player of his caliber should have. He's often listed on most "20 dirtiest players" lists and his time with the Jazz is mentioned as well as his time in Phoenix. So there is a lot we didn't see. I don't think he became known as a dirty player until the Kobe incident. After that he had a reputation and players would try him more, he also wouldn't allow others to get away with much in way of tossing elbows like Kobe. So I think it's sort of the case of 1 incident made the player rather than that incident being part of a string of bad behavior. I remember him getting in quite a few scuffles after that playoff series. So perhaps it's more of how he was viewed and smaller incidents were played up because of who he was. Like if Ron Artest looked at a player funny he would get T'd up for fear of another "Malice in the Palace" incident. He wasn't a choir boy by any means but he couldn't do much after that incident, similar to Bell, without being called out for it.
Here is one list that has him at #10, but it only talks up the Kobe clothesline.
https://www.complex.com/sports/2013/05/the-dirtiest-players-in-nba-history/
Another that talks up the Kobe hit, he's 29
http://bleacherreport.com/articles/530978-the-50-dirtiest-players-in-nba-history?search_query=nba dirtiest players#slide23