It should also be noted that Nick reviewed the paper before publication. In fact, Neil Coleman specifically notes this in the Acknowledgements section: "I thank Nick Hoffman (University of Melbourne) for his valuable comments, for helping me to access MOLA data, and for our congenial discussions in person and through e-mail about volatiles on Mars."

That said, in my opinion Coleman's conclusions are fairly (and flatly) definitive against White Mars. For example:

"The CO2 hypothesis fails to recognize the plausible role of large surface impoundments in creating the largest outflow channels and does not identify a viable mechanism for the recharge of liquid CO2, especially at low latitudes. Clathrates could be stable for long periods at the poles, but analyses of the rheology, morphology, and thermal properties of the polar caps suggest that CO2 is not a major component. Compared with CO2, water is much more stable in crustal reservoirs, and can be released in liquid form by igneous intrusions, volcanic eruptions, and perhaps also by solar insolation.

[...]

"...White Mars claims that, in addition to carving outflow channels, the “cryoclastic” flows smoothed and resurfaced the northern plains. Extreme (100) runout efficiencies would be required just to reach 30°N in the northern plains. Even greater efficiencies would be required to reach middle to high latitudes. Such efficiencies appear unattainable for gas-supported flows on Mars. The notion that gas-supported flows could transport debris hundreds or thousands of kilometers along gentle slopes and also excavate channels that are kilometers deep in bedrock is inconsistent with the limited energy available. This is a fundamental weakness of the White Mars hypothesis."