Is he giving back the Episcopal retirement fund?
For what reason should he give it back? He worked those years, he's due his retirement pension, regardless of where he now choses to worship or work.
Maybe you think he signed a non-compete clause? Or there's some Episcopal secret protected by a non-disclosure agreement?
Has the COE reimbursed the Church for all the property they destroyed and stole after Henry VIIIs temper tantrum?