Hello and thank you for reporting.
After reviewing your demo I don't think I'm going to issue any ban as the player have had a clear ban record since his/hers latest ban from 2016 and due to the fact he let both you as well as some other player get up as soon as he spotted one of you trying to get up. There was also no immediate danger in terms of zombies nearby too. Take in mind that he might not have been focusing on chat and that he might not pay too much attention to the radar/map either so you could've been out of his eyesight if he was being scoped in with his autosniper or he thought you could have gotten up behind him. I'm aware he wasn't standing in the most natural "camping spot" during the demo, but it's not unusual to stand where he was standing when zombies are trying to get up the boxes there (So he might've just wanted to guard the way up for you guys.).
However we will keep an eye on the reported player forward and if you happen to stumble upon this player again breaking any rules please do make a report and a ban will most likely be issued.