I could see him wrecking the one film in the trilogy he actually directed, but he did not direct empire strikes back and return of the jedi.

I cannot believe Kersh let him ruin empire strikes back. As for Marquand he is dead. Does Lucas even have respect for the dead?

He replaced shaw with christensen, why not remove the other directors name and put his on the films.

If i was Kersh i'd disown the special editions of Empire and have allan smithee put in instead.

As for the prequels as far as i'm concerned he can add and deleted things to his liking since they suck anyway, there is nothing he can do to ruin them further.