The only entity which can provide such information with authority is Liberty Reserve itself.
AurumExchange, MtGox and Bitinstant, please, try to contact Liberty Reserve, in an official manner. If they don't respond, try to reach them via lawyers or something. I know it's possible that they'll just ignore the requests, but you'll never be sure if you don't try.
Unfortunately LR will not reply unless legal action is started, which is what we are also waiting for.
AurumXchange however can (and is actually required to) block funds suspected to be in relation of known criminal activity.
True, if nobody reports anything, there won't be any crime, hacker walks away and everything's fine. Thing is we believe there is a high chance that this time legal action will be started, and within that context funds were blocked.
It is not up to any of us to judge if funds should be unlocked, we should have an actual court with an actual judge do an actual investigation first.
If nothing else, these transactions fall very squarely within the requirements for lodging AML suspicious activity reports so there's a chance that they'll be looked at more closely by financial intelligence units even if there are no police reports made.