I don't think that follows. The crew would be acting in accordance with the ship's master (remember, everyone on board is abandoning ship in an orderly manner).

I don't think that follows. The crew would be acting in accordance with the ship's master (remember, everyone on board is abandoning ship in an orderly manner). Someone would surely be liable to the ship's owner but that sounds more like a random tort / breach of contract than a mutiny. In a military they might be AWOL or deserters or something, but they're not in a military. I think you're right about piracy though. Hedora could salvage the now-abandoned ship but I don't think that transfers ownership - it produces something vaguely like a lien. (Presumably space law in _The Expanse_ is different, or maybe the Roci was technically a prize?)