It's definitely dust. We see the same effect on our static DVR cams all the time. That flickering light effect is from the dust particle reflecting the IR light from each of the individual IR bulbs. For us, it's a definite teller.
if it was anything there I believe all the dots would have moved as well on the laser grid...I agree with Wes; could have been dust or an insect passing through....
Probaby either dust or a insect passing through one of the beams from the laser grid being used. They are great for looking for shadows, but create their own set of artifacts.