"Attribute not to malice what can be attributed to stupidity" or "cock-up before conspiracy"
-One of the most important lessons never taught in schools
"The driver just cut me off the prick!"
"Hanlon's Razor, my friend, Hanlon's Razor"
Hanlon's Razor is a saying commonly summarized as "Never assume malice when stupidity will suffice". Named for "Robert Hanlon"--probably a corruption of the author Robert Heinlein. There are many variations, but the general idea is that same. Also known in British English as the "Cock-Up Theory".
Person 1: Dude, my stimulus check was $600 less than it should be. The government is trying to screw me!
Person 2: Hanlon's Razor, man. They probably had faulty information for you.