RAW the only BS Attack that can be resolved against Deployables is with a Deactivator or Minesweeper. The first effect of BS Attack only applies to enemies, Koalas are not enemies. The first effect of BS Attack is necessary for a BS Attack to function.
Dang that Terminology page really messes that up. So are we as a community just in a state of accepting that you can shoot mines with guns despite no real rules back-up?
Yup. That's how I read it. This is why I tell people not to look too closely at the Perimeter Item rules. :)