Not quite. It helps to know what shell shock is.
"Shell shock" is caused by *prolonged* exposure to active warfare, such as when the earth shakes for hours and days, from armor, artillery, bombardment etc.
Shell shocked is just a term people use to describe anyone who has been through a traumatic event and how that event can and does effect your emotional memory. I don’ think the poster was being literal.
Anyway, it’ snot about impugning character is a FACT that witnesses in situations like this are extremely unreliable. Not because they’re lying are idiots. Just because of how the mind works under stress and traumatic situations, and how that absolutely effects one’s memory of that situation/event.
Add to the fact it was dark, people running around screaming, and you add another element that can cause one’s recall memory to be very inaccurate.