Smy, Name...
I do see what both of you are saying, but we were having a very intense game and then he screwed up. I was a very challenging game up to that point, with fighting for position. Took the air out of the balloon after that move. I would've rather have trapped her to kill her... you know the thrill of the hunt.
If you're going to allow takebacks, then you should agree up front on it. THEN, you should relieve the pressure by messaging the move before making it. In a blitz, this is impossible... but, you can eliminate the effect of the error this way with dignity intact.
Alou's official position at this point, I believe, is that he would not have caught it, notwithstanding his post-game interview.
I would be willing to allow an opponent whom I know is certainly capable of a very high level of play, that made an obvious mouse slip while trying to recapture in an obvious exchange, to make the move he/she intended to.
* If you don't think mouse slips are possible....then you probably don't have kids or a demanding spouse...
I don't want or need to beat someone due to them doing something that would be the equivalent of bumping a few pieces while trying to make a move. Why let that sort of thing be your glory ?
But "bumping a few pieces" is only rude, but incurs no penalty unless they are knocked over and not replaced before you hit your clock. "Touch move" only applies to touching a piece "with the intent to move it."
In OTB tournaments, blunders happen all the time, but obviously there are fewer "mouse slips."
If you wish to play this way, that is up to you, but of course they will not be rated because they cannot be serious games.
I meant knocking over pieces, whether before or after you move. I have bumped over pieces trying to reach into a group. With small sets and my large hands, I have trouble getting my fingers around one without bumping another...
I am not such a prick that if you knocked over pieces in an over the board game, that I wouldn't let them be replaced. I don't want to win unless it was my skill that beat you. I don't even like to win when I know someone blundered.
Chess is a perverse game. The only way to win *any* game is if your opponent makes a mistake large enough to lose. That, by most definitions is a blunder.
So, if you feel uncomfortable winning, you may want to try something less competitive. I understand knitting is quite popular.
I don't feel bad if they made a few mistakes and or innacuracies.... according to chess.com's computer, we all do that, even super GM's...
but when my opponent blunders away a piece and it all becomes elementary, I feel like I lost a valuable chance to learn and enjoy winning, more so because of my good play, than their bad play... 
Touch-move is a rule for a reason. If take-backs are allowed, you are not playing chess anymore. Maybe analysis? Maybe double-solitaire? But not chess.
A few weeks ago, I blundered a piece in an unrated, OTB, skittles game. My opponent offered to let me take the move back. I declined because: if I had accepted and gone on to "win" the game, who really won? Me? Or my opponent? If I win, I want to DESERVE the win. If I lose, I want to deserve that too.
yeah, I agree that your opponent's move was a blunder.... sometimes I will make a move that I figured out was bad, but forgot 2 days later..... it is often a bishop from a world away too that gets me.....