I would need a lot more information than this youtube and the scant reporting done on CeeCee Lyles, and her husband Lorne. I don't know the source of this audio, or whether or not Lorne has proof (like an electronic log of his cell phone captured IDs with dates). It could be a stewardess helping CeeCee make the call and saying "you did great." Or it could be someone next to her saying that about something one of the other passengers had just done.
There may be interesting data here, but it needs a lot more scrutiny than this. The mere fact that the video's producers are jumping to all sorts of wild conclusions without more information is also helpful in determining how we should treat this material.
On the video's information side bar, I see a link to Info Wars, where anything can become dramatic information with the slightest amount of imagination.
I don't know anything about this material, and it's not sourced, referenced, or corroborated in the video. As for the husband, he's an unreliable witness due to the emotional nature of the event.
Yet, the video would lead us to the point that we can envision mass shootings on the ground. Don't you see a problem with this kind of material?
9:27 a.m. September 11, 2001: Flight 93 Passenger Tom Burnett Calls Wife Using Cell Phone; Reports that His Plane Has Been Hijacked
Tom Burnett, a passenger on board Flight 93, calls his wife Deena Burnett at their home in San Ramon, California. (Longman 2002, pp. 106-107) She looks at the caller ID and recognizes the number as being that of his cell phone. She asks him if he is OK, and he replies: No, Im not. Im on an airplane thats been hijacked. He says, They just knifed a guy, and adds that this person was a passenger.
According to Deena Burnett, her husband called her on a cell phone at altitude. This was a physical impossibility. It was so significant, the government lied to cover it up. The government claimed Burnett used an Airphone.
Who would you believe? The wife of the man on the plane or the government that has a history of lies concerning events of mass murder like Waco and the OKC bombing?
If she saved the cell phone bill or could get the records, that would indeed be a smoking gun, since the government is on record in the Moussaoui trial claiming the call came from a GTE Airphone.