Change the question. Instead of asking what made you angry, ask what threatened, confused or unsettled you.

What the research says

In a study of people's dominant response to a traumatic event, many reported anger, guilt, sadness or numbness rather than fear, and those responses still predicted post-traumatic symptoms afterwards. So anger is often what sits on the surface of a threatening event. The study was cross-sectional and relied on people recalling how they had felt, which is not a precise instrument.

Strength of evidence: one line of research. A single study, or a theoretical account.