Massive visual bugs

IMPORTANT: This is NOT necessarily related to the user's hardware; after he restarted the game it worked fine. I seem to recall something similar happening to me a while back (though I may be remembering it wrong so don't take my word for it), and I have an NVIDIA graphics card (Alienware laptop). I do not know how to reproduce the bug; it seems to happen randomly.

Attached are nine screenshots, the log file from when the bug was happening, and another log file from after a game restart. The "GL ERROR" appears on both logs, so I'm not sure that's related. I've also attached a manual debug crash log taken later in the same version. Ignore the IndexOutOfBoundsExceptions in normal-log.log; that's due to a bug with /clone that I'll report after this if nobody else has done so.

ALSO: The user who had this problem was not me, but we were in a Skype call when it happened. He didn't want/know how to report the bug, so I did it for him.