I noticed that occasionally, in Single-Player, I suddenly just die and then respawn as a bird (spectator). Then a quote that says "Good birds don't run away" at the bottom of the screen once this happens. Reloading from the last save will fix this, but this is a pretty annoying intrusion to the gaming experience. I've only experienced this once in the campaign so far. I'm wondering if anyone else notices this.
Also, I think I actually noticed a bug in the re-arming feature. Before a mission, when you select your arms, I think I managed to make one M136 AT4 round and a satchel charge actually DISAPPEAR from existence. I'll try it again to make sure, though, but I'm fairly confident I started with 4 AT4 rounds in stock and somehow ended up with 3. This was the mission in which you have to destroy a couple of enemy armor, near the beginning of the campaign.