Guild Wars 2

I won a game, though one of my Teammates DC for about 2 minutes, I got desertion as well, and lost a pip DESPITE winning the game. Any reason for this?

The only thing I can think of is that the enemy team has a lot lower MMR than your team, which means you should have crushed them. That and your personal score is really low.

If your teammate was partied with you, it is a known bug and a fix is on the way.