Yeah sure the king came out. I'd still not call it a gambit, this is a far cry from a Smith Morra or a Budapest gambit. Or a Vucoviç gambit where white sometimes gives up the Queen for 3 pieces.

If I captured a Knight with my Queen and failed to see it could be recaptured, I'd definitely say I blundered my Queen. Even when people go cave exploring on b7 and get a pawn+Rook for the Queen, it's a blunder and leads to a clearly winning position.

Nothing is ever free in Chess, capturing a Queen will always cost at least 1 tempo.

Some people will resign, but everyone came to play and miracles do happen. But you agreed on that, so I think we're on the same page.