No, he booted to his DVD, and then did a password reset ('i'm 95% sure') from the utilities menu.
Because it was outside of System Pref, he's going to be permanently locked out of the keychain unless he can remember again.
Again, if it were not for this, then anyone could force-break into any keychain simply by a terminal command. And if it were that easy, then I'm sure we'd all know it by now, and he probably wouldn't be asking for a method on if it's even possible to brute-force it 😝
Even with a super-computer, I don't think it's going to happen in his life-time.