I can't find any reference in the AR to the EDL contract having any pre-payment, do you have a source? It looks to me that the three deferred commitments are to PWC, Macquarie's pre-purchase, and Mereenie gas balancing (also to Macquarie, as JV partner).
In the AR, the first line of Note 15 appears to contradict your interpretation of 15 (b):
"Proceeds received under Take-or-Pay contracts where gas is able to be taken by the customer in future periods:"
So reading Note 15 in its entirety it appears that CTP recognises revenue when PWC forfeits delivery under take-or-pay, but that PWC is entitled to take that gas at a later date (which, as discussed, is unusual for a take-or-pay contract). It appears that PWC has on-sold the gas and received revenue for it, so CTP needs to deliver that gas at its own expense, which is presumably the liability on the balance sheet.
I don't recall RC or the company ever explaining this was a deferred delivery take-or-pay contract, except buried in this note in the Annual Report.
