Becoming appalled and deeply indignant even though completely in the wrong.
A delusion is a false belief strongly held in spite of invalidating evidence. Self-deluded indignation goes one step further by demonstrating actual indignation towards the person with the correct, sane and rational position.
1. “I told the nurse she’d given me the wrong lab results and she went off on me explaining how she was the trained medical professional and that I was just an untrained layman. The problem with that of course is that she had actually given me the wrong fucking lab results!”
2. “Self-deluded indignation.”