I think a moderately important exception about law enforcement might need to be "a lot of the time, the lowest uncontroversial law enforcement can be trusted". This is the tone of my response to everything from that "don't talk to cops" lawyer video all over youtube, to just talking to cops randomly while getting lost on the streets of NY City. As long as it's "painfully easy" with no wrinkles, then you can (mostly!) trust them.
It's just the minute when it gets complicated that things begin to get hazy.