I'm surprised that Travis Ford let him sit on the bench and then have to deal with fans storming the court being in his agitated state. Definitely could have exploded into something much worse.
I was thinking the same thing initially but I think that's a bit of hindsight being 20/20. The refs did not believe he needed to be ejected. He was still eligible to be playing. At the time the foul is called it's a one possession game if I recall correctly. What if OSU forces OT. Do you then go get Smart from the locker room to come back and play? If it doesn't at what point do you give up on the game and send him back to the locker room? If it was so bad Smart needed to be off the court the refs are the ones that messed up, not Ford.