The AFK check

I was in champ select with a 4 man premade when i got a notification saying my computer had a mandatory restart. Granted I should research how to delay this but the only option it gives me is do it now or wait 15 minutes. So anyway my team tells me to just wait till loading screen and restart and just be a minute or two late to the game after I offered to dodge. So I do as they ask but once the game starts our one friend who has a tendency to feed dies twice at 2 minutes. So he rages and hits the AFK check to which the random in our game votes yes. My concern is that I am now on leaverbuster and took a huge hit to my lp based off something that he had asked me to do and he trolled me. The FAQ says that I can get banned after one or two games but want to know how I can check this especially after my so called friend trolled me.