Drums and guitar generally layered perfectly, however since the drums are more prominent, if there was any negligible difference the drums would take priority. Any difference greater than that (like near the intro) would be combated with colored notes. And if differences exceed that, then drum syncing is dropped entirely, leaving tempo changes only for the guitar/keyboard. This is exemplified on measure 41. 

Any guitar segment that was significantly distorted by speed reduction (like measures 9 through 12) had to be stepped close to 1x rate to ensure accuracy.
