Thanks for the link, at least politifact has links to view.

Politifact links this electronic intifada article which uses the testimony of survivor Yasmin Porat and this Haaretz article among others as evidence of friendly fire. I don’t see the video mentioned as evidence here. It seems like the only source provided for the video not showing any friendly fire is from an IDF spokesperson. So I can’t say either way without more independent verification.

I did find this electronic intifada article which does show some Twitter posts with the video. The Twitter posts do falsely claim that the video is about the NOVA Festival. The article also states:

As The Times of Israel reported on 15 October, the army published video claiming it shows “helicopter gunships striking Hamas terrorists as they streamed across the breached border from Gaza” on 7 October

I do agree that it’s irresponsible to show those tweets without clarifying the video isn’t about the NOVA Festival. But I don’t see any Electronic Intifada article stating “Footage from Israeli helicopter shows the IDF killing many people at October 7 concert in Israel.” from what I found