And by "irrationality" I mean it doesn't necessarily involve thought. Indeed, if you have to think about a reaction to an immediate deadly threat, you're probably dead already (if not in any given instance, then over the long run).
That's part of why analyzing events like this from the comfort of our keyboard is missing the point; an unthinking decision to flee or freeze is just as likely to be right (or wrong) as an unthinking decision to fight. That plays into discussions of both blaming (or drawing moral conclusions) from these kind of events as well as of confidently being sure that, Hey, if only I'd been there, I'd have been able to be the hero.
Why Nobody Intervened in the July 4 Metro Murder
Criticism of witnesses’ inaction reflects a fundamental misunderstanding of the neuroscience of how the brain responds to sudden threats