Well from what little we can assume, Gruden probably purposely sent those emails, where Rugg probably didn't purposely crash.
Clearly killing someone is worse, but I don't see bashing Gruden harder based on intent as a big deal. Also they're both former Raiders now.
Now back to whom leaked these... more than I think about it, less I think it's Goodell and either someone that secretly supports the Union leader (as the timing helped him) or the Redskins owner(s).
Also note, it's been suggested that there were two different leaks, one leaked the Gruden emails and the other the NFL lawyer emails.
With WTF owners wife (who's the acting owner) supposively claiming (unprompted) that the leaks did not come from her or her husband. Depending on which report you read, she was either referencing the Gruden leaks or both sets or leaks.
Either way, that's not completely true, as the owner literally filed some of the emails in a
public court document months earlier, though media hadn't picked up on it yet.
And only emails from Bruce Allen have been made public, and I believe Allen won a court case over money from Dan Synder. And Dan Synder is infamous for holding grudges, and probably didn't like Allen or Gruden, with whom he hired Gruden's brother as head coach. And with all the legal BS, Synder probably hated the NFL lawyer as well...
And NFL owners supposively didn't think the owner did it himself, but possibly that someone working for him did... on his behalf.
Short version, I think WFT owner is more likely the one to blame than Goodell (just my opinion).