Leaver penalty after reconnecting

In my most recent game I happened to bug splat (pretty common not upset about this) but upon reconnecting the enemy was encroaching on our nexus. So as a perfectly sane person, I dodge the enemies abilities as I am the only one alive (rest of team got aced while dc'd). I didn't happen to leave fountain when the game ended because of course, I didn't want to die. The enemy team ended and upon reaching the lobby I was given a leaver buster after a 40 minute game. I understand that this is somewhat intended because of AFKs and such but I don't think I went wrong anywhere. Not incredibly mad but I hope something can be done in the future to prevent this.

(End game lobby) https://www.flickr.com/photos/161858872@N05/39913094553/in/dateposted-public/