I don't really care why you went AFK. I'll report you anyways.
I don't care if your kid had a nightmare, I don't care if your house burned down, I don't care if your cat knocked over a row of glasses, I don't care if you've got a stomach bug and couldn't hold it anymore. I'm gonna report you.
I do this because, well, if this doesn't happen frequently, it shouldn't be an issue. If this DOES happen frequently, then you deserve the ban because you shouldn't be playing at those times since you can't commit to a full game.