I thought flexon was just very springy metal, not nitinol. Nitinol is not very rigid, it bends easily. And even though it snaps back when heated, it's not perfect -- I've got a few toys made of the stuff and after a while they get damaged and don't return perfectly to the original shape.
Sounds pretty legit to me unless I see something else saying otherwise. I think they just stress the titanium of it as a lot of consumers probably think of titanium as a "space age" futuristic metal that they make space ships and the SR-71 and Lt. Dan's legs out of. Saying its made of Nitinol means nothing to a lot of average consumers.