Well, to be honest they are all meant to have a foot plate.
However I have seen one other, a 30b Han Bespin that did not have one, so it is possible, though all other Ugnaughts and Han Bespins I have seen do have the footplate.
With the later 45a you find certain characters consistently don't, such as Vader and Dengar. My C3P0 doesn't either, and there is no real reason I can think of as to why this should be the case for these figures.
Do you think the lifting at the top was enough to get the figure out?