Conditional moves issue/suggestion


I have been on sites where players have a 'takeback' and 'request takeback' button.
In the event of error, playerA hits the request button and playerB can agree to retract the game to before playerA's last move by pressing the takeback button. Of course, he doesn't have to (if he feels playerA is simply trying to cheat !), but in the case of obvious error (say Kf1 instead of 0-0) this is a definite aid.
Not sure if I've got this right, but when I enter a conditional move it seems to take the moves without a commit?
What I mean is, that I'm worried in case I enter the wrong conditional move and this is automatically commited as a line without me specifically doing submit as I do in a normal move?
Is this right? If so, if I accidentally enterered a wrong move (say due to dodgy mouse...don't ask?!) then if my opponent moved while I was entering (which often happens when you get 2/3 moves when you're both online), then am I stuck with the accidental move?
If so, wouldn't it be easier to have a conditional moves commit button? In other words, you could enter all your lines, but they wouldn't be "live" until you hit the commit button.
...or have I got this wrong?