The problem is when mistakes, honest or otherwise, are made by people empowered with the means of lethal force. Some professions have much smaller margins for mistakes than others, and I say that as a former US Army military police captain and the son of a retired municipal cop from the Pittsburgh suburbs.
Yes. Cops should be held to the very highest standard and they are not.
Nine of my 20 years in the Air Force I was on Missile Combat Crew. We lived underground and had the keys and Sealed Authenticators needed to launch ICBMs. Our training and operating standards were zero error...ever.
Cops may not have the ability to destroy entire cities and countries but they have the ability to kill people so they should be held to the same standards.