Yeah, but maybe Ray or Peter turned on Egon's PACK in the elevator and Egon turned on his wand when he got off the elevator. I say this because in the episode Knock Knock, the guys switch on the packs with a button the back of the pack and then turn on the wands, but then again RGB isn't in canon with the movies.
The only other conclusion I can come to is that the packs have the option of being turned on by the pack or the wand and Knock Knock goofed when they had the guys turn on the packs a second time.
I dunno, these little inconsistencies bug me when they probably shouldn't.