For all the flack the prequels get, RotS has always been held in higher esteem than the other two. So I think it is reasonable to reconcile between that film and the OT, even if I feel Eps 1 and 2 should be made to match the rest.

Rather than use that as a reasoning, I'd point to Yoda telling Luke he must "confront" Vader, giving the impression of initiating a battle. Also, Obi-Wan stating that if Luke will not kill Vader, "The Emperor has already won". Both statements give reasonable support to a Jedi being the aggressor in a battle.