Well, if they think it is appendicitis and go in for an appendix, they always remove it, even if it is OK. This is because if they didn't take it out, the patient would be left with an appendix scar which would suggest very strongly to another surgeon on a later occasion when the patient might not be compos mentis, that their appendix had been removed. .....so, that would rule out appendicitis as the diagnosis.
Which would be dangerous....if they still had an appendix.
The answer was, that shell shock was not recognised as a genuine medical condition during World War One. Sympathetic surgeons removed perfectly healthy appedixes from shell shocked victims so they could be sent home on medical grounds.