Rant: Loss Avoidance and Full Playthroughs

Okay, this is two parts; a rant, and a question. I'll rant first.

Start Rant http://matchhistory.na.leagueoflegends.com/en/#match-details/NA1/1723495947/33533335?tab=overview So I'm playing a match in which the enemy team has a pretty powerful team; they are fairly tanky and it's difficult to win team fights against them. Some point middle of the match their Riven disconnects. Despite that, they last a good while against us. After we finally win a good team match that allows us to push the inhibitor turrets, their team starts complaining about the 4v5, Riven being disconnected, and how it was unfair (they soon degrade to complaining about lag and misclicking, but I digress). My problem with this is that if they were so crippled by not having a full team, why didn't they forfeit? What's the use of complaining about losing due to a handicap if you were so fine playing with said handicap when you were able to perform VERY well despite that (they caught several people in my team, including myself, in 3-4 man ganks). I just find it annoying as hell people want to complain about how my win doesn't count when it's a 4v5, yet they had no intentions of surrendering due to it. End Rant

So my question is this: If this would've been a ranked match, that would've hurt the LP of 4 unlucky players. Isn't there a way to prevent losses due to this? In the instance of this match, I feel it is fully their responsibility for not surrendering, and they should've taken their lp loss due to it. But if a team is down a man, and they surrender, they should be able to avoid the loss.