Because I apparently have the time for this sort of thing, here's what I noticed on today's episode, a lot of which is corroborated above: None of the contestants come on down with a mic on, so when one of the first four contestants plays game #1, he/she is not wearing a mic. By the time the second contestant comes down, everyone is wearing one. If a contestant comes on down and doesn't win that immediate one-bid, he is mic'd by the next one-bid.
No contestant won their immediate one-bid outside of the first one, so I didn't get to see what happens, if anything, if a later contestant comes up right away.