...for a CEO is a little more complicated than y'all think. It has to be done via notice with the SEC and usually done over time..especially if the sales are large.
Insider trading for major execs could be charged for an unplanned sale (or buy) with a short time period of major announcements. Most of the convictions come from buys...but this guy could go down on the sale.
Falsifying records is what got the CFO canned already...and will likely end up costing Arthur Anderson a penny or 2 as well...since it appears that they signed off on these statements.
This situation will be better understood as more of the records make it into the public eye. It sounds to me like they were eseentially gambling on electricity futures...trying to hedge with derivatives...and doing it on money that apparently wasn't there....so it, in all, was one big clusterf***