Some politician just resigned from office because an affair he had was exposed. (He's married, and so is the woman.) In his resignation, he referred to his "mistake".
Man, I'm sick of deliberate, vile acts being referred to as mistakes. Sometimes it's what amounts to treason, as in the case Iran-Contra. In that case, Ronald Reagan, that slimy bastard, even pushed it all off into the fuzzy world of the passive voice: "Mistakes were made." More often, "mistake" is used to refer to a personal transgression - cheating on one's spouse or robbing a Seven Eleven. Relatives and supporters will even tell us that the slimeball in question "has learned from his mistakes."
Well, no. He hasn't. Not if he's still calling his evil actions "mistakes".
A mistake is an oversight, like dropping a letter in the mailbox without having put a stamp on it. Or it can be an action based on misinformation, like showing up at the theater on the wrong day or time because you saw an out-of-date showtime listing. "Mistake" doesn't apply to walking into a convenience store with a gun in your pocket. And you don't slip your willy into someone else's receptacle, or vice versa, by mistake. You do it on purpose, usually with planning or at least a few minutes of foreknowlege, and always, unless you're astonishingly stupid, with full knowledge of the terrible injury you're doing.
But maybe it depends on who's evaluating the actions. Relatives and friends of the holdup man or cheater may be willing to minimize the transgression as a mistake. Republicans are remarkably willing to excuse the actions of Republican officeholders.