Qualified immunity is for civil repercussions, not criminal. Individual police officers can go to jail for committing crimes in the line of duty. Any civil lawsuits stemming from such acts, however, cannot be aimed at the individual officer, but must instead be against the city/state/feds. I’m skeptical that letting officers get sued for things they can already go to jail for would be a major additional deterrent.

(To be clear, I’m in favor of ending qualified immunity in cases associated with criminal acts, not because I think it will make things better, but because it is fundamentally unjust for the taxpayers to be forced to cover the bill for an individual officer’s illegal acts, when the officer — of all people — should have known that the act was illegal)

That's just another reason for everyone to be recording.