Collapse shot from unknown chopper, similar to WCBS chopper 2 recording.
At 14:30 in video:
For comparison: WCBS Chopper 2 clip from NIST:
Recorded from much further away or lesser zoomed in, at least. Also shot more from south-southwestern direction than CBS2 chopper. Is that maybe Long Island News Chopper 12?
Frame taken from closing credits of the BoHG documentary:
See WNYW NIST Dub #3 for CUMULUS clips in Release #14 on 911datasets.org, or low quality MP4 video file "502-WTCI-435-I.mp4" on NIST WTC website, shows video after the towers collapse:
http://wtcdata.nist.gov/gallery2/v/Coll ... I.mp4.html
Still frame from NIST CUMULUS clip "WNYW Dub3 10", frame 3912.
(NIST FOIA 09-42, Release #14 - Uncomprssed Set, 911datasets.org):