Saturn V,
Some of the other defendents like the IBM VP or the McKenzie consultant also did not directy trade in AMD, but were still charged for inappropriate disclosure of information
After reading the WSJ article, it looks like they were charged with conspiracy. The question is: conspiracy to what? It could not be to profit directly, so I guess it must have been something else.
As for Ruiz, if the investigation uncovers other leaks by him to Wall St, then perhaps the leaks were intentional to affect AMD's stock and perhaps the AMD stock (its behavior, price or perception by analyst) was a key component to having the deal go through? I don't know. This is clearly deep speculation on my part, but hey you never know.
IMHO