The demo is too short and doesn't provide enough information. He has a really quick shot when you go around that wall and the other shot is really fishy because you're jumping, either way it's only 2 shots both from your perspective. He also just has 25 hours of playtime in tf2, from which 24.7 hours is in the last 2 weeks.
He probably is a hacker, but this demo sadly doesn't prove that. If we're not sure in something we better not do it. So I think this report is invalid although the temptation of banning this guy is pretty big.