I think he is... and he has a good point... I imagine co2/h2o clathrates would be violently unstable once pressure on them is lessened...could this be the mechanism behind the recent findings of what looks like recent liquid outflows? Methane clathrates are found on the ocean floor-and when brought up to the surface they practically explode!

Picture the following scenario and tell me if you think it makes sense:
A small part of a crater wall gives way, exposing a layer of the clathrate...with the pressure released and exposed to solar heating it violently dissociates and gushes out and down the crater wall...a fizzing muddy slurry...

would the before and after pics look like this: