I'm afraid the truth is more boring: it's just a slightly misplayed 3/4 bar. It occurs during the guitar solo section and is actually very clearly 3/4 there. Du

I'm afraid the truth is more boring: it's just a slightly misplayed 3/4 bar. It occurs during the guitar solo section and is actually very clearly 3/4 there. During the verses they just play it a little faster, probably because they weren't actually fully aware that they were turning it into a 3/4 bar, they just found a riff they liked and played it slightly faster because it sounded cool. That's really it.