So, question of if they’re safe or not will come down to HOW they did the reverse engineering. If the same engineers that delved into the jailbroken iOS devices are the ones that wrote the code (which seems likely given the prototype came from a single person), they’re going to be in trouble. If they implemented a “clean room” reverse engineering though, then they’re likely safe from being sued over copyright violations. See Wiki
So, question of if they’re safe or not will come down to HOW they did the reverse engineering. If the same engineers that delved into the jailbroken iOS devices are the ones that wrote the code (which seems likely given the prototype came from a single person), they’re going to be in trouble. If they implemented a “clean room” reverse engineering though, then they’re likely safe from being sued over copyright violations. See Wiki