The sailor comes out of the building towing a suitcase but after he kisses his girlfriend the shot widens and the suitcase is gone.
There is absolutely no possibility that anyone could have recognised Ducky, at a glance, after nearly 20 years, wearing a hat, in profile and from behind (possibly with a view of the top of his head).
Everyone just kind of forgot that the whole story made no sense once Ducky surrendered.