guy decides to feed,because we had an afk??

So today i decided to hop on some ranked matches, i got bot lane ,everything went well until this happened: (support) guys i have too go,my grandpa had an accident" ok i get it shit happens in life, so we tell him to afk so we can remake. This happened around 1 min. Now 3 mins hit the remake system didn't go and our mid laner ( ) decided to give a first blood.(ok i know i know maybe he didn't know we couldn't remake and 1 kill isn't that big). But our top laner was doing fine and myself was doing great, considering i had too 1v2. But everything changed when this decided too feed feed feed , and he would say "gg"we lost"4v5 we lost" we can't win" while i was 2-0, was 1-0 was doing decent helping out. And throughout the whole match he continually said that and we eventually lost the match. I just want to point out that players need to stop thinking that just because it's a 4v5 doesn't mean it's a lost match. And it seems weird but when you say "we lost" it plays with your head and gives you the mentality to lose your match than to win. I know it's just 1 match but players need too think a bit more straight when they decide to queue up for ranked. You don't joke in ranked, it's serious. And when you come in a ranked match with that attitude of losing and later on you complain too your friends that you are stuck in "elo hell"/lower elo" and you blame your team it's your own fault for having that mindset of losing. Hope you summoners think about this situation i shared. Have a nice day :)