Power abuse happens on a very lesser level than it always has. Any potental technical flaws in an anti-corruption system will be exploited to the limit.
Yep, which is why you continue to improve and enforce those anti-corruption systems, they, like all organisations, will bitch and scream and kick at anyone else holding authority over them, but if that authority doesn't fall apart from, say, public apathy
*cough*, they'll submit to the new rules eventually. Then they'll abuse those new rules to the fullest yes, but then we just tighten up those new loopholes in subsequent inquests and reforms, don't we? The only key is public support. If the public think 'well we'll never change it, no point trying' then they make it true through apathy. If they protest and push and petition and so forth, things are forced to change. Maybe slowly, but they do.
I actually agree with your point on the kid being traumatized anyway, but that's just a symptom of the screwed system. Were it to happen to me or my children I would sue on every single count I could, because that really would fuck up the kid's sense of security, let alone faith in the police services to protect them. Also mine. Of course, I'd probably have been shot at the scene anyway, because my pets are parts of my family (small, intellectually disabled family) and I would have lost it completely if they'd been killed by a pack of deadshit gunmen.
edit: THIS THREAD IS GOING TOO FAST SLOW DOWN AGH
edit2: just to clarify, those loopholes we assume the police will be exploting? yes, new ones might pop up every time there's a reform but they usually won't be worse ones. The old loophole might've been that they can, say, arrest anyone they want at any time with as much force as they want (extreme example, not reflecting on anyone in particular) and not get in trouble if anyone dies 'resisting arrest'. The new loophole might be that they are required to provide thourough proof of a need to use their weapons during an arrest, but not really get in trouble if they can't. After a third reform, they might only be able to use non-lethal methods, but can instead beat the shit out of anyone 'resisting arrest'.
It can continue forever potentially (and will, knowing how humans are), but don't you think the increasing standards are a good thing? At the end of 3 reforms, these magical corrupt policemen no longer shoot 50 people a year, they only beat to death 15. Hooray progress!