Personally I suspect said fan said something racist towards him (because I don't see Marcus Smart reacting that way otherwise) and that seems to be what's reported. Now should he have shoved him? No but I can't really fault him either.

And in case you are wondering Metta World Peace did weigh in on this(who better to ask?)

@smart_MS3 all mistakes and missteps are a foundation for improvement. Sometimes the game is so intense , we forget its just a game.

Metta World Peace (@MettaWorldPeace) February 9, 2014