of course they ban manual but its not a vac ban its called shadowban i have 7,1k mmr acc banned cause of ddosing dota2 servers.
Source? Proof? There isn't any, is there? Because all of it are just illusions.
1) Last year, Valve implemented a automated system to detect server crashers. The system basically checks how likely your games are crashed and matches it with information like; guy played 10 games today, 5 win and 5 unscored (which is unlikely to happen in normal situation, right?) and shadow ban if there is a match. It still is a automated system and not a manual ban.
So there is only detection bans and Valve never takes a crappy video that an redditor uploaded into consideration to ban people.