See 0:49 - 0:53, 1:46 - 1:51, and various other parts.
I've heard people do stuff like this before but I don't think I've actually ever seen someone do it, like watched them.
On an unrelated note I love this guy's lead tone. The tone he has from 2:58 - 3:35 is fucking awesome.
Man the guy got his shit together.