Well...
This has happened to me also but,
The problem resides in riot not being able to actually tell the difference between trolls and those who actually are having problems.
The game itself has built in spammer protections to help keep it even when someone dc's (like the total xp you would receive stays the same, and at one time in league history the minions got stronger or something to that effect) but no matter what you will only ever have the 4 players abilities versus the 5 players abilities.
i would really like to see this problem fixed or at least alleviated by having a script or something to see how quickly the person in question tries to reconnect (the time between last game server communication to the first login server communication), but even then you could have someone just turn off their computer and re-login a few time just to mess with you...
In the cases of hardware failures or bad over-clocks, they could put a subroutine in, an anti-cheat program, so that it sees whether or not you have done something yourself or if the system threw an exception, but that means a new piece of software with administrator privileges that potentially could get hacked in a number of ways and that would be yet another program running in the background slowing down a toaster machine.
They could have a separate server pinging your LAN card or your personal networks gateway but that means an increase in traffic and there is no true way to tell when your houses power got shut off versus when the troll unplugged their router, not to mention that may be infringing n the isp's terms of use and there would be a whole new debacle there...
All of these solutions DO NOT fix the problem!!!
The Root of the problem is the people's disrespect/inconsideration/untruthfulness that comes with those few abusers out of any group of people.
These types of people(trolls/abusers) aren't following the summoners code (still a thing right?) and those people that have been affected by trolls have whined to riot. Riot in turn, has put these measures in place to try to reduce spammers but those measures catch the honest mistakes and problems that arise out of these complex boxes called computers.
Bottom line is if people were honest and respected other human beings the Tribunal would never had to be made.
That being said, you are in a team game that your team mates rely on you and that being said you need to have stable reliable equipment too, for those that dont i kinda think ranked is not a great place to be but that is what normals are for. i used to have a verrrrry bad toaster but i didn't do ranked because i know my teams counted on me. now i have a great computer and im slowly climbing the Elo ladder.
The times that this has happened to me its been a fluke, so I am not mad about the system, which is what it sounds like happend with you... maybe if you call them they will take that mark off your record??
I definitely Sympathize with you, but i hope you understand the respecting fellow teammates part too !^.^!