The second MouseUp is consumed by the DoublePressed event. It’s a bit annoying, but easy to code around. Just treat DoublePressed as another MouseUp.
I was confused at first, too, but I’m not sure how else they’d implement it unless they followed suit and added a Pressed event and both acted independently of MouseDown and MouseUp, which I would prefer to the current functionality.
No, I’m saying a user could code their own handling of DoublePresses by using Mouse events, and DoublePressed would still also fire. I think they were trying to avoid something that should’ve been made easier by separating the functionality.
And also, most peoples code has not yet been ported to Desktop API, so this will brake their code when they make the jump. And even in new apps this creates bug, me finding it was in new Application, which again made me look in components I have and find the problem all over.
Further more then usually for code then missing MouseUp is more destructive than a MouseUp that the code did not expect. Since the missing one tends to leave the UI in limbo. (If not having counter measures as Anthony suggest above)