It seems to me that, depending on the situation, the third reaction (above) may be the best option, or possibly even the only reasonable option.
In fact, unless I’m mistaken, I recall seeing this option recommended somewhere in the FIDE rules.
If my opponent is a habitual clock-press-forgetter, the first couple of times he forgets, I will remind him. After that, I figure it’s his problem, and he needs to learn somehow.
BUT – first I want to make sure he has really forgotten. So, I’ll wait for a while, probably 30 seconds at least, and then try to judge from his body language. Or, if the position calls for a long think, I’ll take as long as I want, and if he continues to forget, I’ll eventually invoke the aforementioned move-press-press option. I have NEVER had an opponent object. In fact, I don’t think I’ve ever had an opponent even notice the double-press.
On a few occasions, it has even slipped my mind (or, once in a great while, I myself haven’t noticed) that my opponent hasn’t pressed. In such a case, once I’ve played my move and then noticed his clock running, there’s not really anything else I could do other than move-press-press.
I wouldn’t want to just move, and omit the double-press, because then I would be depriving both my opponent and myself of entitled increment time (not to mention the move count if it’s a two-control event).
Was the player supposedly contemplating making a draw offer, or accepting a draw offer already made by the opponent?
- If the former, the player should have completed his contemplating before moving. For that matter, I suppose he could still make the offer even after moving, and if the opponent then whines about the player’s out-of-sequence draw offer, the player (or TD) could point out that the opponent’s move-press-press was itself slightly irregular, so there should be no penalty imposed for the out-of-sequence offer.
- If the latter, it could be pointed out to the player that, by moving, he has already declined the draw offer, so tough bananas.
Bill Smythe