Treat it like what it is, oot action. Since the raise is not complete, action is not yet on MP, so his call is oot action. So when action is changed MP gets back his 600 and retains all options.

What if MP is deaf? Since dealer did not halt the action and make the raise right MP has no way of knowing there was a raise. Nothing about throwing out a single chip, large enough to call but not of ridiculous size raises any immediate question. If he put out a 1,000,000 chip, then maybe it is odd enough one should ask for clarification.

+1

Dammit, I wish I had thought of that.

At FW they make any money that goes in, stay in. Even though the player who limped can argue that the action wasn't complete it was in fact complete. The player just didn't hear it and the Dealer didn't say it out loud. But by saying "raise" and tossing out 1,000 the raise amount is 1,200. There can be no question about that.

In the spirit of friendliness when I am in the hand, I will always offer the option for the player to take back their chips. When the dealer is at fault like in this case they will often overlook the rule to force the chips to stay. If another player gets nitty then the chips will have to stay almost always (Floor decisions may vary at FW the very wonder of it all);

As Evil noted I don't think the calling player can be given the option to raise because of their initial call. So I would not allow "A".

Something I do as a matter of course when a Dealer fails to announce "Raise" or at least when I don't hear it, is that I immediately ask the dealer if they know its a raise. I would say about half the time (maybe less but I like to think I am important) they were unaware that the word "raise" had been said. I do this whether I am in the hand or not. If this situation can be avoided so much the better.