Surprised that it would be a "hassle" because this should be a common occurrence for daily-valued plans, but I agree with Lou's suggestion in his last sentence if push comes to shove.
It needs to run through the trust and he needs to receive a 1099-R. Ask the broker to put it in writing that he'll personally indemnify the Plan Sponsor for any all penalties that may arise from the Plan Sponsor Paying the participant directly outside the Plan.
I'm not sure why it's a problem reopening the account but you can open an account in the name of the Plan anywhere and pay it out from there.