The "dick move" isn't actually a dick move. You seem to be referring to the world where time moves back and forth as you go left and right. It actually makes perfect sense with that time mechanic.
If you've got the puzzle piece between two doors, and you use a key to open the door on the right, it DOES begin to open, except as soon as you move the slightest bit left, time reverses to the point in which the door was closed, and if it's a "time-immune" key, then it can't revert to a non-used state.
x=locked door
p=puzzle piece
o=open door
k=key (time-immune)
uk=used key (time-immune)
As Tim moves left (and time moves backwards):
|x|(p)|x|(k)
|x|(p)|o|(uk)
|x|(p)|x|(uk)
In other words, if you try moving left (backwards in time), then the moment after you unlock the door, you've locked it again. And since the key is magic, once it's used, it's used for all time.
Make sense?
Sorry that was so huge, but that particular criticism always bothered me because it was absolutely invalid, and Yahtzee usually seems like the smart enough type who have figured out why it happened before ranting about it.
Otherwise, spot-on!