As commented in the cap :
Suspect Invert Mouse events
Expected behavior is that when you left click a Case(sprite, layer 0) and that it's already have a CaseObst(sprite, layer 1) on it, it wouldn't create another one. Though it does.
When you right click, it should create the CasePF(sprite, layer 1) on click, and leave it in place. Though as soon as click his done (even maintaining the button done, not releasing it), CasePF seems to disappear (though it exists in the DOM).