Riot supports trolls but not people who have emergencies

SO I had to leave a game because I needed to take my grandma to the hospital and when I get back I'm in low priority queue. I'm adc and I get a troll support zed who takes all cs and doesn't help in fights. A teammate also said that he was a troll mf support the game before. LIke really riot? you don't ban guys like him but I have a legit reason for leaving and I get pinged with lpq off the bat? #supporttrolls