Typically speaking, when considering a backup the trigger and the potential
for them to get a second shot at it are both things that you want to
evaluate when making your decision to back up.
When you back up to a point in the game and then let the players play on
you should expect them to play the game from there the way it naturally
would occur. In the case of backing up to the untap step the player will
proceed through their upkeep and the confidant will trigger. They may or
may not forget/miss the trigger at that point and that isn't our problem unless the opponent wants to call attention to the trigger.
In the end if you are not comfortable backing up through the upkeep and
giving them the second go around on the trigger then the answer becomes
leave as-is and move on. I however have no problem just backing up to the
untap and going from there, don't say anything about the trigger, just let
them play the game the way they will (as long as it is legal).
Edited Patrick Cool (Feb. 12, 2015 10:09:02 AM)