MIN chart, page-155

I am surmising it was part of Chris's contingency plan and related to bullet points 1 & 3

I wouldn't be surprised if Chris had his eye on the next venture and may have wanted money at the ready to deploy in case whatever he had his eye on arose before he completed the haul road deal.

This arrangement might have been wriiten up in such a way that if he did draw down the US$750 he would repay JP Morgan with the proceeds of the 1.2 billion once the funds were cleared

A similar setup to a bridging loan when you buy a house and are still waiting for the money to hit your account from selling your old house

Just a guess as the annoucement says it's is being cancelled upon or before the haul road's transaction completion