kick somebody when they're down

kick (one) when (one) is down

To criticize, exploit, insult, or otherwise treat badly someone who has already suffered a setback or is in a vulnerable position. Can Jeff's employee review wait until next week? His girlfriend just left him, and I don't want to kick him while he's down. A: "I'm sorry you got fired, but you shouldn't have been so sloppy with your work." B: "Wow, way to kick me when I'm down."
See also: down, kick

kick somebody when they’re ˈdown

continue to hurt somebody when they are already defeated, etc: George generally believed that you should never kick a man when he’s down, but thought that this time he might make an exception.
See also: down, kick, somebody