I have heard of grandmasters playing black and asking for a draw before the game even starts and then getting it.
1) they need to go
2) mouse slip
3) frustration
4) impatience (long game and opponent refuses draw)
5) sandbagging
Nothing i hate more than f*#king sandbaggers
Its not that even of a position...black might have the same material but his knight is badly placed and overworked, with the additional problem of a fully isolated pawn. Probably at GM level it's resignable or quite close to it.