LeaverBuster still bans you after you recconect!

So here's the case, today I was playing a game, while I was playing I remembered I had to go somewhere for like 5 mins, as I did and after 5 mins I was back the system had already given me that prolonged inactivity msg and i click ok when it says to log me out, after a couple of minutes I recconect and I am gladly seeing that my team is winning, I immediately start playing again, after some minutes we finally won the game, even though i recconected and my team won I still got 20 mins ban for 5 games, LeaverBuster does it's job well and changes the behavior of players I agree on that, but if there isnt any ''bad'' behavior to be punished why is it doing so...?