@hakunoyuuki Back in 8th grade or something the whole class had a similar "numbness" (dunno the correct English term) in an extreme case.
It was chemistry class and the teacher messed up and experiment. Her cloths went on fire and it was a chemical which couldnt easily be extinguished. Out of 25 to 30 students only 2 reacted. The whole other class was just sitting there and couldnt grasp the situation. One student was aware enough to get a fire blanket and save her while another girl went running to get help from other teachers.
Its not like we didnt want to save her, but we just didnt know what to do at this point. After the event it was clear, but not at that exact moment. I personally didnt like these 2 students, who were adept enough to help, but I still have high respect for them, that they knew what to do and could react. Thinking back to it, it probably was kind of like a herd behavior. Because most of the students didnt react, you didnt react too.
To prevent this, you actually have to train these situations. Later on when I was 18 I made my driver's license and to be able to do the test, you have to solve a first aid class. Imo this should be done way more often and also already in school starting at 5th class or so.
Ofc this here is a different situation, but the feeling of being overwhelmed is the same. Thats also why something like astronaut or firefighting training takes so many years. You have to rely on routines you practiced and adept to them and cant think forever to grasp the situation.