>The problem you're describing is only a problem with Act on Press, which is why it's normally Act on Release, so I don't understand how it's irrelevant to his point.
No, it is also a problem with act on release. How do you distinguish a drag and a click?
If you release while still inside the button it's a click. Try dragging a random clickable element in the browser (like dragging a link into this comment box) and you will see the same behaviour.
No, it is also a problem with act on release. How do you distinguish a drag and a click?