This is not a lawsuit. This is reporting the facts to the police and they will decide whether there is a criminal case against Bitcoin Consultancy. Completely separate from any civil litigation. I'm not sure there necessarily is a criminal case here (not a lawyer), but there certainly could be (fraud, theft, criminal negligence)
Reports should be made regardless of whether people believe Bitcoinica is at fault.
Somebody stole those funds and that theft warrants investigation by law enforcement. In the past, people have rightly assumed that there would be no legal consequences for stealing Bitcoins - which only encourages further attempts. Whether or not any prosecutions result, there desperately needs to be a full, external investigation of the recent Bitcoinica losses.