I can not confirm what you say because even mhorner on his site he doesn't confirm this. In a topic by dyxum only one time mhorner spoke exactly about what you said now. So for me if i can not get any decent results i can not confirm it i can just say i have heard from mhorner that ADI can work also with no D/DT lens but not always accurate.
You can easily test if it is true...
Put 5 contact lens on camera.
Put camera on tripod and point it at a plain bit of wall.
Set camera to manual exposure and heavily underexpose (so that only flash is lighting the subject).
Set flash metering to ADI
Manual focus to infinity - expose.
Manual focus to closest focus - expose.
If it is purely TTL then both shots will be the same.
If it uses distance information then the infinity focus will be over exposed and the close focus one under exposed.
This happens on my A100 with 50mm f/1.7, but I do not have a more recent camera body to test it on.