fix #4091

guess what, this wasn't QUITE as simple as "Cause a widget caught the event."

NOTE: I am *THIS* close to ripping out all of the ill-considered
unmaintainable spaghetti threading bullshit code paths once and
for all (GML, LoadingMT, ALL OF THEM) if I have to fix one more
of these goddamn bugs that certain other people like to dismiss
out of hand AND DO NOTHING ABOUT