I don't know if I would have made the right play here, but i wouldn't have limped, even if i am on the button. When a couple of players in mid position are in the hand, i dont like to try to abuse the power of the button. If just one person was in there, i would wonder why they limped in middle position and not raised. I would assume they have a very decent starting hand, and didn't want to scare people by betting in a position where you must have a good hand to play.
But, I am the farthest thing from the person you want answering this post, just sayin what I would do..