I see some lights in the background of the top picture that I dont see in the second one... I'd say you just caught a bad reflection off something. Could be a small imperfection in your lens that reflected light weird, or else something as simple as dust/hair real close to the lens and out of focus.
In the second picture, if you look at the tree on the left hand side where it's darkest, you'll see another light colored blob, looks very much like lit up dust to me. The flash reflected off something (the big white stone in front of it) and gave some weird lighting to a particle in the air.
Theres something going on with your camera or the environment... again in the second picture on the left hand side of the tree (about half an inch above the blur I pointed out) you've got a little red hotspot.
