HP have to do this, because it was either that or the board resign en masses for total incompetence.
By the time all the appeals are done, they'll have retired - so everything is fine.
It's not like they're going to get much in the way of compensation out of Lynch. It's possible they could squeeze a few hundred million out of him, but that's not going to make up for their claimed $8bn loss. Although a few hundred million here and a few hundred million there - and soon you're talking serious money.