Nice emblem noob.
Just remember that 'host-booting' can take many forms and does not require the offending player to actually be the host in order to do anything. External 'booters' simply require an IP, something which can easily be obtained via programs such as C&A.
I was the first to 'lag out' of that game, and the method by which everyone's names 'blacked out' as I left is unlike anything I've seen, considering DeathClutch was AFK in a hiding spot whilst this took place supports your claim he could have done something, however I have doubts to this also due to previously playing against him with no such cheating occurring.
TL;DR DeathClutch is bad at Halo and if he does do this, he does it out of necessity for being so garbage.