KJUmp wrotePerhaps, an NBA rule dictated that they had no choice in the matter...the refs walk off with the .2 left on the clock and they face a fine form the league.
Just speculating.
The officials handled this correctly by rule. By rule, they have to put .2 back on the clock w/the shot clock violation. By rule, there has to be 5 players on the court for each team...or it's a technical foul.