I saw this in a different thread. Shots at flyers are like Feel no Pain. Feel no pain overrides all previous rules and does so after all over affects. Likewise, shooting a flyer is always reduced to snap shots after all other affect have been applied. In other words PotMS does give you full BS, and then it's made into a snap shot.
The other argument is that snap shots are a special rule that ignores BS all together, so it doesn't matter what the BS is.
Whatever Fickles your tancy.