I think it's similar to how people freeze up when an emergency happens. There's no logic behind it - more like too many thoughts and feelings flooding the mind

I think it's similar to how people freeze up when an emergency happens. There's no logic behind it - more like too many thoughts and feelings flooding the mind at once, resulting in paralysis. You are probably the fortunate few who can maintain some semblance of clarity in stressful situations. Over the years I've watched people react to stress (myself included) and it's not always as straightforward as you see it. Maybe the bystander effect is a form of paralysis. Doubt, lack of knowledge, fear for one's own safety, it's just easier to do nothing - all those thoughts are flooding the system.