IME, direct flight nearly always include a change of aircraft. UA examples abound:
881 IAD-ORD 757 ORD-NRT 747
914 MSY-IAD 727 IAD-CDG 777
Well, the list goes on and on...

In these cases, the only reasons I can see to call these "direct" rather than "connections" is to fool customers who dont understand the difference between nonstop and direct and to penalize us by taking miles. Maybe there is some slot thing where the "originating city" makes a difference, but that'd be news to me...

As was posted in one of the other boards at an earlier time: the reason for designating the flight direct as opposed to connecting is to get it listed first or ahead of other airlines connecting flights on the different travel booking sites.