Compassion Rage
Overboiling anger in response to a stimulus that is intended to provoke a compassionate response. A more robust relative of Compassion Fatigue, which may also be followed by Rage Fatigue.
"When that guy asked me 'Big Isssue, sir? Would you like to help the homeless', I screamed at him 'don't fucking try and socially engineer me with your claim that giving you £1.40 is going to solve homelessness!' I'm normally such a nice guy. I don't understand myself. Maybe it was compassion rage."