During Second chance:
Flying Blood texture when you leave the building the level begins in (and when they showcase the nanosuit it's visor to you). Can be found, when you look on the ground when you exit the door directly on your left (will make screenshots when I get around to)
The part, where the Cell soldier gets swarmed by those small Ceph insects doesn't work properly all the time. Occasionally the Soldier will, while the action is happening, disrupt the animation (looks very odd) and hit one of the Insects (and thus saving himself and immediately start shooting at you). From what I have noticed, this doesn't happen when you approach them cloaked.
The other part, after you learned how to use armor mode and you overview the next larger area (where Cell soldiers are talking about burning bodies). The AI seems to be able to spot you through the large roadblock, even when your sitting behind the cover of it (I'm talking about the upper parts of the barrier, not the entire barrier itself). Now I haven't tested out, if this applies too all such road blocks.
During Road Rage:
Right at the start there is a small subway entrance you can walk through. Around the same time a chopper flies bye and starts shooting at me although I'm am underground and he shouldn't even be able to see me. Now I understand that they have thermal visions, and can thus see you if your cloaked. But they shouldn't be able to see me when I'm standing underground.
After you get on the highway (and before the Earthquake breaks the street) a couple of soldiers are waiting to ambush you. On the right side of them (from the view of the player) a larger part of the grass is flying rather then being connected to the ground.
During Corporate Collapse:
Occasionally, even though Chino tells you at the beginning "Let's move out", neither him nor the other marine will move at all. Restarting the level itself doesn't help, only starting the level before that, and finishing it allowed me to circumvent it.
During Train to catch and Unsafe Haven and possibly other levels with a lot of friendly AI frequently respawning:
Some Human AI soldiers (US Marines) won't have a gun in their hands, even though they are holding their hands as if they would have. When they shoot, their bullets come out of the weapon they carry on their back (which looks rather strange). It may be connected to them using grenades but deciding not to throw them, since I Have seen them sometimes holding their hands in the described posture while holding a grenade in one of them but not throwing it.