Hmm...

Thanks to being at university I did eventually figure out how to access the full paper. The main part of interest appears to be this paragraph:

A digital computerized EEG performed 5 h following the arrest was isoelectric using gains of 7 µV/mm (Fig. 1). Reconfiguring the study using double distance electrode placement confirmed the absence of cortical activity. At maximal gains of 2 µV/mm there was extensive EKG, respirator and muscle artifact, but no demonstrable cerebral electrical activity. Median nerve SSEP performed immediately thereafter were normal (Fig. 2).

I'm not a biology major, unfortunately, but what I take this to mean is that the EEG detected no electrical activity although the rest of the nervous system (heart, muscles, lungs, etc.) were working normally, and also that signals emitted by the nervous system from stimulus were correctly transmitted throughout the brain. So while the brain had no self-sustaining electrical activity its signal response was good (which actually ought to indicate just that the neural structure and functionality -- the stuff that cryonics is meant to preserve -- was good!).

But, again, I don't study biology and most of the terms they use are new to me, so I could have misinterpreted. Still, I take this as some evidence that not much of importance is stored in volatile electrical activity.