After watching the full thing on rumble, it looks to me like the guy was doing his usual “anti racist virtue signal” by tackling the good samaritan that was restraining the knife wielder to show off to the female police. Unfortunately for him, this time it massively blew up into his face, and neck.
(Or maybe he was hoping the asset would finish the job but the asset came after him instead.)
The person that greenlit the concept needs to be fired (as well as plenty of other people).