Proper lockdown quitter etiquette

So the other day I'm playing some lockdown, and it's a 4v4. I lie, it was a 4v3 even in the waiting room, someone didn't even make it that far into the match.
Anyway, someone hits the "fill 'er up" on Krogmo, and the prize is revealed to be a Ruby Bombhead Mask. I start feeling sorry for the other team already, because the bombhead masks are pretty darn rare rewards (though to be fair, this particular one is, I believe, available from Sullivan, so it wasn't as bad as it could have been), and I can tell that my team (I happened to be on the 4 side of the 4v3) is at least decked out in decent gear.
The game goes very predictably. They make a good effort, but we stomp all over them because they're down a player. We've all seen how it goes, I needn't go into the gory details.
After the match is over and we've won our bombhead mask, I apologize to the other team for kicking their butts, and try to in some small way let them know that I feel their pain and am glad they at least stuck with it through the match and didn't all rage quit.
However, one of the other guys on my team chides me for apologizing. When I pointed out that the other team was down a player (he hadn't noticed at first) he was like "oh, well, you still shouldn't apologize".
So what's the general consensus? Is apologizing to the other team when they're down a player or two and miss out on a good reward appropriate? Patronizing? Welcome? Unneeded?

It's always kind to apologize if the teams are unbalanced, or if something like that happens. There are very few people who can take loosing gracefully, and those people who can should be applauded for their good sportsmanship!
It's not needed, no, but a welcome surprise if it does come, IMO. It makes those people more likely to continue sticking it out and not RQ'ing, because they've had reinforcement that it's the right thing, and that other people appreciate it.
The only problem is if the other team suddenly decides it's sarcasm. Hopefully not, though. Good on ya for thanking them for sticking it out. This stuff makes the community better!

Sportsmanship is sportsmanship, no matter what the "sport" happens to be. Its all about not having hard feelings, a competition that is meant to ultimately be friendly and should stay that way.
Football and baseball players shake hands after each match, and tell each other good game. Play is always balanced, and everyone, from the coaches to the players to the audience, prefer it both sides were evenly distributed, and were given an equal and fair shake and coming out on top.
Personally, I always wish everyone in the lobby best of luck on the playing field. And that does mean everyone. I encourage them to play and fight their hardest, and I go in with a good attitude. I play hard, then when the match is over, regardless of whether my team won or lost, I tell them it was a good match. If there are leavers on the opposing team, I sincerely apologize on the behalf of circumstance (it helps knowing how badly leavers can suck for your team).
There is no reason not to treat your opponents with respect. They too, are people, and human beings who, like you, are trying to win. To wit, it is my belief that they ought be afforded the respect that you'd want given to yourself.
If people on my team (or the opposing, for that matter) are talking trash and being classless [jerks], I typically tell them to cut it out and show a little class. Nobody likes a braggart, no one is impressed by a showboater, and nobody enjoys being talked down to.
It goes without saying that a truly skilled player will let his abilities (and in this case, end-match capture/damage numbers) speak for them, and have no need to talk trash, or put others down.
So, you know.
Keep it classy, guys. The PVP in this game isn't like PVP in most other games out there. Let's keep it that way.

What Omird says x2.
When someone sulks or boasts, I usually chime in with a "You win some, you lose some" comment to try to remind them that there are more games than the one we just played.
Apologizing seems fine, unless it was over the top..? Perhaps the person felt it was a pity statement directed to the losers and considered it "salt in the wounds."
I usually would just go for a blanket statement about how leavers suck for a game (regardless of whether I win or lose) and joke about spam telling a rage-quitter.
There will be many chances to win bombheads in the future, so no need to make a bigger deal out of it compared to a normal game with a leaver in it. It's not like the other 3 players were playing lockdown specifically to receive a ruby bombhead. Pointing to the man-advantage more than normal may be what the other person was against? (Purely speculating, as I wasn't there.)
probably unneeded, but I usually make a comment if everyone on the winning side (whether I'm the lucky one or not) is all like "gggggggggggggggggggg" and there were players missing.
I also /clap upon winning and losing