What I meant is that the fallout from an air burst is only made of the remnants of the warhead's casing, fission products and un-fissioned material. The extent of this fallout is limited to the mass of the weapon, and from surface knowledge I have, it's minimized in modern nuclear weapons (this fallout is essentially wasted mass and unrealized explosive potential). The end effect of this fallout is primarily raising the global cancer risk a tiny bit.
The usual thing people think of as "fallout" is the result of low-altitude detonation, where the explosion draws up dirt/dust/water vapor, makes some of that radioactive, and creates a cloud of radioactive particulates that then settles in a large area downwind of the explosion. This is the massively dangerous fallout that's usually associated with nuclear weapons.
TL;DR: air bursts != ground-level bursts, and if one doesn't know about the energy scale difference involved, it doesn't seem so dumb to ask if detonating a nuke high up in the cyclone would be helpful.