Track 2, 30: Left guitar plays last two notes of measure 
a half step lower than the right-panned guitar. It sounds 
like a fretting mistake but listen closely and you'll hear 
it's intentionally played this way for most of the song.

Both parts, 31: The series of notes on the F string is 
correct. I can't tell if the "harmony" is the half step 
below or above. These are definitely chords, not 
harmonized by two guitars. [Repeated at bar 106.]

Both parts, 101-102: I can't make out the harmony on 
the final four chords of the riff. It could be that one 
guitar plays standard power chords while the other 
plays the same chord except with the minor 6th (for 
example, D root and Bb harmony).

Both parts, 103: Like bar 31, only the tempo/pulse is 
different. As with bar 31, I'm not totally sure of the 
harmony.

Track 2, 105: As far as I can tell, both guitars play this 
in unison for the rest of the song. Weird.