Personally I don't think he was wall hacking.
The last but where he killed red bull was the only bit which looked slightly odd but I watched this with music playing so I can't really judge that.
The other clips beforehand seem clean to me and not very wall hack like but he lags a tonne.
So my opinion based on what I have seen is clean.
EDIT: There's some areas which I find slightly funny, like when he aims at people at B from Mid/Tspawn but that's where you generally look when going around the corner to check someone coming from mid.
Also the part where red bull runs, you could see his foot if you pay attention which is kinda hard to spot when playing, but if focused whilst playing, you could make it out indicating where he had hidden.
To be honest, I hardly think that this guy would WH because he doesn't seem like the type, but then again I could be wrong :/
Also, more opinions appreciated as I would like to finalize my claim.