Japanese Air Base Ghost Video

This video was taking by a security camera at Kadena Air base in Japan, well kind of, it shows a dark figure that kind of looks like peoples. The dudes who you can hear in the video give the video a good analyzing.

At the very end it does look like the figure is much smaller and closer to the camera than perceived, maybe a bird or bug?

I'd love to know what the focus is like really close to security cameras, I'd imagine it can't be very good.