Yes, their science is off -- but I would go further and say that this is actually the worst possible shape for cooling drinks, because the ratio of surface area to volume is lower in a sphere than any other shape. What you want is the opposite: lots of surface area (to cool the drink quickly) and little volume (to avoid diluting the drink). That's at least part of the reason for the shapes of common restaurant ice-maker ice cubes, or so I've heard -- like the flat ones or the thimble-shaped ones. Lots of surface area, little volume.

Looks cool, but as for keeping drinks cool -- not so much.