According to Wikipedia:

"Blouses (and many women's shirts with buttons) usually have buttons reversed from that of men's shirts...

Another possible reason is so men can easily undo blouses as, from the front, buttons are on the same side as a men's shirt"

I tried to find a citation for this but could not.

I think someone's trying to screw around, especially since the phrasing for most of the other explanations was stolen from one source.