Any of the criminals involved in this should already know: returning the funds doesn't mean this is over. This isn't over until justice has been served.
Regardless of who actually committed the MtGox heist, the proceeds were laundered through AurumXchange and Liberty Reserve. Those businesses have their own best interests to consider and aren't necessarily going to drop this just because Bitcoinica customers would be satisfied with the funds being returned.
Unfortunately, my friend (the source of legitimate LR funds) does not wish to be involved in this disaster because he is supposed to be irrelevant. He's fine with providing information to the authorities, but definitely not to the Bitcoin community after he has read this thread.
I absolutely agree that he shouldn't be expected to provide any information to this community. His details are only relevant for the purpose of proving the origin of the funds for the LR transactions and it's those conducting any AML investigation who need to satisfied as to the legitimacy of those funds, not this community.