Well the parts with the snare on the downbeats are alternating between 7/4 and two bars of 4/4 (I want to say 8/4 but that's just weird, lol. Simpler to say, though...)
As for the weird changes... My counting skills are not advanced enough and I'm not confident enough in my ability to keep steady internal time without being affected by external changes to really say what's going on. I tried tapping through the "steady" section and the confusing section and it seemed to stay lined up when the steady section comes back in again.
Edit: That doesn't really help much but it's thread activity at least...