Yeah, he just made the sound completely fit into the video, if you listen to these songs, they won't be that good as on Inc 2, the sound of aiming makes songs even greater which is amazingly perfect.
And about "people playing named as clayman", that's not true, I've seen him on ESL match live (SourceTV), and according to his steamID, he definitely was Clayman.
P.s.: Exis Steam acc vlaka?