The second I doubt because it's rather easy to "wash" the bitcoins and the robed person would have a hard case proving that he was robbed and not just sent the bitcoins to another address himself.
Brave new world.
Sounds like another "new" crime: False claim of bitcoin theft.
Obviously these are all variants on flavors of crime as old as humanity, but the law creates nuances that influence how the police respond, how the courts sentence, and how restitutions are pursued.
A crime would be proven by proving the coercion leading to the initial transfer. Which suggests a business idea: People are going to get threatened to reveal their passcodes. Just as alarm systems have codes that visually disarm them while silently signalling help, a bitcoin wallet should have a passcode that unlocks it but simultaneously alerts law enforcement. For example, a mobile wallet opening with a panic passcode might simultaneously transfer the majority of its balance to a safe address and also send a text message to police with its location. The wallet could even record sound and video, forwarding it to the police and off device copying.
With the perpetrator presumably under arrest, the coin has stopped moving. Assuming they had a way to recover the loot, let them sit in jail until they divulge the addresses and keys.