Leaver Buster Warning?

The other night I was playing a pre-made 5-man with friends when my power goes out, leaving me hanging in the middle (20mins in) of a match. I log on today to see a Leaver Buster warning, forcing me against my will to state that I acknowledge that I abandoned my teammates and that I won't do it again. I understand there's no real way to check if someone had a legitimate reason for going afk, but the fact I was in a pre-made with friends I know personally and that this was the first time this year I've gone AFK makes it a little ridiculous that I got a warning over that one instance.

Long story short, I'm not an AFK'er or dodger, and I'd like to know if this is going to affect me at all, or if I could petition to have this thing removed from my record.