No, he wasn't fully burried, and he could of still got air, because the moss let's it through. Nothing fast moved near him, the only thing I can think of, is that he was looking out of the tank, and saw me open the room door, which might scare him..?
Once I put him in water, he was back to normal, and I've been watching him closely today, and he's fine, no abnormal breathing.
Thanks for the info!
~Royce