Current reporting is that Musk approached the White House with the idea. Of course in reality the White House holds all ultimate responsibility, but that doesn't mean Musk is without guilt (especially if he proposed the idea for... some reason...?)
Why should Musk feel guilty about an administration's decision that he has no influence over?
I don't care whether he feels guilty. He is guilty. And as described above (as well as in many ways not described above), he does have influence over it.