The Pentagon Surveillance Video-- Disinformation?

This video, supposedly showing flight 77 hitting the Pentagon followed by a large explosion, is strange and has been analyzed by many 9/11 researchers. It can be seen at Eric Bart's site for instance.

The most obvious odd things about the video are:
1) the date is wrong-- 9/12
2) key frames seem to be missing
3) the lighting changes in some frames suggesting it has been altered digitally
4) the shape of the explosion, which should have emitted only from the entry hole, is very symmetrically placed over the top of the building, suggesting the explosion was added in digitally.

Why would the Pentagon release such an obviously strange video?

1) they are covering something up but very sloppily
or
2) the video is pure disinformation designed to throw 9/11 researchers off track

My tendency is to think the latter. I mean, why release it at all if it so obviously weird?