What he did it's creating a lobby with 9 other players, and each team would throw in turn so both teams can win bets and do battle pass / guild quests. They would use the balance team option in a private lobby, creating 2 parties of 5, then go queue on an obsolete server, like Dubai or India. When they eventually match vs each other, they will just have one team win first, then the other team win after, and so on so on.
He only picks heroes he don't normally play in these games to lose, so it doesn't affect the winrate on heroes he's good at. There's just no way, that a divine ranked player, would go 11-75 on a hero, no matter how ridiculous the reason is. There's a 20-60-20 rules in DotA that people might be familiar with, and that is if you're playing at your own skill bracket, 20% of your games will be won no matter what you do (you get carried, smurfs on your team, etc), another 20% of your games will be lost no matter what you do (enemy teams smurfing, your teammates griefing/int feeding, etc), and the rest of the games (60%) it's where you can actually change the outcome with your gameplays.
So unless OP is insanely bad and unlucky at the same time (which i doubt it, given his rank, and the large sample size), there's just no way to go 11-75 on a specific hero, especially WW. WW is not an easy hero to master, but her spell kit is definitely not rocket sciences, especially compared to heroes like Meepo, Invoker, and Visage. An average DotA player of this rank will take about 5-10 games to learn a new hero, and maybe 15-20 to master it. So going 11-75 is statistically impossible, unless you're doing abuse lobbies during TI, or you're intentionally throwing those games.
So the conclusion is that he's just showing evidence that he did some battle pass abuses during the TIs, or he's griefing whenever he plays WW. And to OP, if that's not the case, can you please link your Dotabuff so we can see what's going on in those games ? u/Joan_Hawk