the examples you're giving seem to be about victims of abuse or assault or misconduct not coming forward. that's different, as thr power imbalance is explicit and already being weaponized against them.It's not just about believing someone else will help. In these instances it involves power imbalances, possible freeze responses etc. With a veteran cop vs a rookie the power imbalances creates a bystander effect. The police are humans, they're not immune to human responses. Does it suck? Yes. Is it A good enough excuse? No. But in some cases this is why police are complicit. Same reason female officers rarely speak up over male colleagues. The nuance of power imbalance creating fear. The whole thing needs overhauling.
Its the same reason Bill Cosby and Jimmy saville got away with abuse. Power over others and so a fear of speaking up. What power does a rookie have? You fall in line or you get turned on yourself.
but anybody that wasn't already being victimized and allowed it to go on to save their job? because they were worried they might face repercussions so they'd rather let someone else be abused or assaulted or raped or killed? they're dead fucking wrong, and they get no understanding.
power is a continuum, and rookie or no they had a lot more of it than George Floyd did.