Dota2, love it or hate it, is a game filled with a glorious amount of players trying to find that thing that will allow them to gain an edge over one another. I don't know if you could say another game promotes innovation more than Dota2. I am sure someone will though.
Anyway, in typical Valve fashion, you can get items through playing the game that can be traded and used in various ways. And, also in typical Valve fashion, there are events for holidays and the most recent holiday was Halloween. The event in Dota2 for Halloween was called Diretide and if you managed to be the fastest group to kill a particular enemy in the game, you could be rewarded with a tiny version of it as a prize.
This prize, the Golden Baby Roshan, recently went for as high as 1000 dollars over on Reddit. You can read more about the loopholes and strategies players are taking at PCGamesN.
So, that Reddit transaction paired with all 10 players in a Dota2 game working together to get one of these items decreased the fastest time to an insane degree. When all was said and done, one group managed to manipulate the time it took to kill the monster to .09 seconds or less than a 1/10 of a second. These players managed to do this because they found a way to damage the NPC before the timer actually started. The loophole was closed after a patch, but it may only be a matter of time before players find a new loophole to take advantage of.
One of my favorite pictures from the hall of fame for killing Roshan the fastest:
