In manga they always say "dont worry, I used the backside of the blade" when fighting non-lethally, even if they are drawn with double-edged swords. I think we finally found out why that is. Had they used the flat side instead, their enemies would have gone splat.
@fenrire yup. Probably too unused to swords, so she picked the side that couldn't accidentally be the back side of the sword (maybe unable to tell the difference between the edge and the back) to ensure it wouldn't survive.