Time delays wont work inside of an IF statements on exported version.
You may need to split that out so that you time delays work. otherwise its always going to fire the false statements immediately after the true statement.
try this
If score = "correct"
Set visible of PaintObject "yes" to true
Else
Set visible of PaintObject "no" to true
End if
Delay 3000 ms
Set visible of PaintObject "yes" to false