Hi Abel,
The graders will score your AWA based on whatever is on the screen when your time ran out. A couple of minor errors (typos, grammar, etc.) won't swing your score much (if at all), but if there are a notable number of those little errors then you could conceivably lose half a point from your overall score. That having been said, if you stayed on topic and wrote with even a bit of 'depth', then you should have no problem scoring at least a 4.0 (and that's all that most Business Schools expect for 'minimum competency').
GMAT assassins aren't born, they're made,
Rich