I'm a total newbie here, but from what I gather, to assert the term "Thug" as a term with racist implications, in this context is completely unfair. Surely there may be a social context in some situations, however, the word thug is defined as a violent person, criminal... and it transcends race.
That said, while they weren't thugs in the sense that they committed violent crimes, I think it is very fair to equate "thuggery" with their style of play, i.e. choking, fighting, on the court violence, etc.