<Original post has been edited out because of it being completely irrelevant now>
After running in with some odd behavior from CreatePointTrigger, after some more experimentation, I've determined that that's probably the natural behavior of this trigger type.
It appears that the CreatePointTrigger will fire for both its specified coordinates (x,y), as well as for (x-1,y) A plain map with one unit and one trigger should be a safe enough test.
Nothing else I can say at the moment.
