Dave,
If he checked, of course, he can raise...but then we wouldn't be talking about a skipped player. The way I see it: If Adam is skipped by Billy Bob and Carly... with Billy Bob betting out of turn, at the time of Billy Bob's OOT Adam, or the dealer or any other player should have said something to correct the action to the proper bettor. I'm sorry I can not agree with giving Adam the option to raise in this situation. I've always felt that once a proper bettor is skipped he or she should be allowed to immediately correct the mistake and back up the action to, in this case, Adam. TDA rules do not support backing up the action, even before the substantial action occurs.