This is what I was thinking. I thought flinch could only take effect if the pokemon using the flinch inducing move was faster. That's why I was confused. I don't even understand how this would work unless, unbeknownst to most, recharge effectively acts as a third move within the turn after your opponent attacks?
EDIT: Just looked through the thread, and a few posts back was another user asking the same thing I did, as they were in the same situation. Apparently it isn't a bug, but can we get actual confirmation that this is how cartridge works? Is there a thread detailing this anywhere?