There is a code in tooltip that ignores MouseExited events if they have the same coordinates as the previous mouse event. It was added as a fix for RT-14798, and this issue suggests there are more such pieces of code elsewhere.

This is not correct. The MouseExited event is not "bogus", it is delivered because something else appears under the cursor (tooltip in this case). The solution is to pop up the tooltip elsewhere, not to ignore the event. The events are completely OK and should be handled normally, if the mouse doesn't move but the control is animated out from it, the tooltip should be hidden too, shouldn't it? I don't know what the other occurrences do but I would expect similar problems there.