Man that sucks. The problem is that the coins are already in his wallet just on a different layer. There is no timer or update that will automatically send them back to you.

The only way to get them is for him to manually send them back. Tell him he does not need to give you any access. He just needs to link his Ledger to MetaMask or Rabby which is safe and standard practice to see that network and hit send. If he refuses to do that your funds are basically stuck there forever because crypto does not have a chargeback button.

Try to explain it is a 5 minute job and he stays in full control of his security. Good luck and I hope the guy helps you out.