My first thought when you talked about this was that maybe someone set up a trial account they could play against and get wins against so they could drive up their score.
I just did some research however and found that the player with the worst glicko rating is named Warboy, and he has 113 losses no wins. Probably who you're talking about. Looking at his record, it seems pretty legitamite... he must just surrender as soon as anything bad happens, or he started way too many challenges and is getting timed out all over the place. Hard to tell.
Here's the page with his glicko stats:
If you want to see the glicko rating system in general its here:
Basically, this rating system is much more realistic in determining the skill level of someone than the in-game system, which gives you points for every game whether you win or lose (more of an experience indicator than a skill indicator). Glicko takes into account who you play, how much better or worse they are than you, and whether they are established players (the RD value). You can basically think that the scores are actually their score +- the RD value listed for them.