Weird glitch in ONLINE chess


I was recently playing a game against a friend in online chess; not a tournament or anything, just for leisure.

After a tight game, he unfortunately made an error that left him behind in material and led him to resign after I suggested he do so. However, after he resigned and our ratings and no. of games played had been adjusted, the game CONTINUED!?

Not knowing what was going on, we both played on and some moves later he tried to resign again. When he resigned again the game finally did end, but our ratings were adjusted AGAIN!? So I gained double the points and he lost double the points for ONE game.

Has anybody had a similar experience, is this a bug or just a freak occurence? If anyone knows anything about this please let me know because I think it's a really unfair thing to happen [even if I did get a nice boost to my score!] and if it is a bug, needs to know about it asap before it happens to anyone else.