Blame the game for putting him in there, he didn't choose to be put into your game.
Do you know how P2P works? if he is red barring for you it doesn't "necessarily" mean he's red barring for everyone .
What it means is that the connection between both of you is laggy. If he is teleporting all over the screen for you then that happens due to packet loss between the observant party and the party involved in question. Let's assume that it's due to his connection that is causing packet loss. What makes you think that the packet loss will only affect his movements for others but at the same time will have consistent movement for everyone else (including your own) on HIS game? Remember his connection to you and others is laggy meaning he cannot upload his movement properly nor can he download your movements properly.
It's not as simple as "this guy is teleporting so he has super powers...even though I might joke about it while actually playing."
Try doing this, try to join a friend's party who is in a completely different continent far away like australia or east asia (maybe have some of his other friends from that region in the party to make sure the host is from that region too). Play with him and you'll notice that when you lag yourself other people will teleport for you but the game will be completely fine for everyone else except when dealing with you who will be teleporting and skipping everyone from their POV. This is the nature of how P2P works, it's not the same as dedicated servers where everyone's connection is to one central server.
Minimum is 10Mbps? lol you are completely incorrect.
Games with online heavy functionality that are data hungry like Destiny, World of Warcraft only use up 100-200MB of data per hour (for less heavy games like COD it's around 20-40MB per hour) which is completely manageable on a 512kbps connection and as such increased speed won't do jack, perhaps try measuring how much data Destiny consumes per hour before claiming that 10mbps is the minimum requirement for gaming.
For your info, I originally come from India where I gamed on a 512 kbps internet connection for YEARS and played on servers on singapore with 50-60ms of delay which is normal. Connection speed is NOT directly related to latency. Even now when I go and visit my parents I play Team Fortress 2 on a 2Mbps connection and the experience is no different for me than how it used to be...nor is it any different from how it is when I play here from UK on local servers. Because I am playing on servers based near my location. Proximity to server and the networking efficiency is what counts. If you have 50ms of lag to a server on a 10mbps connection it won't become any less even if you upgrade it to 100mbps.
This is anecdotal stuff and there is no valid proof behind this reasoning I see lots red bar people do terrible all the time, there is no correlation here if there is then I'd like you to provide proof. A bit more about my experiences, which could be considered anecdotal as well were it not for the fact that I have experienced playing from the other side which I assume you never have (judging by how you think 10mbps is minimum for online games ). I never used to play console games in India because of matchmaking which would put me into western servers and hence give me a laggy connection, if a laggy connection indeed provided me with an advantage then I would never have stopped playing it....I would always do horrible. Also lag switching works different to the lag I am discussing about here as it's only one way which can only be achieved when done deliberately.
You will not understand it unless you have experienced it yourself, I have experienced it and as such I can tell you that your perception is incorrect. The very nature of my situation required me to experiment and learn about this to a level most people do not bother. But I can tell you this that laggy connection will not make things easy for you because it is difficult for you to shoot people who are teleporting everywhere and yes people do teleport everywhere even for the laggers.
