Thanks for the ad hominem.
It would have been more plausible if you didn't claim to know better than the know-it-all in the next sentence ("willfully").
If you really want this discussion then perhaps take into consideration the nature of the crime and try to recall your own youth (you've once been 18, too, right?).
I'm not saying he doesn't deserve a slap on the wrist. It's however beyond ridiculous to try and charge him with virtual 9 figure damages - potentially sending him to jail and ruining the rest of his life.
The more interesting question is who was charged for criminal negligence - or at least fired - at Valve over this?
This is the more interesting question because curious and slightly naive 18yr olds are a natural law. They will always be around, and there's strong evidence that deterrence does not work very well against them.