I doubt they paid with MO's. A $28k purchase with anything other than a credit card is likely to involve supervisor intervention. 28x 1k MO's or 46x 500's would set off all sorts of alarms.
Instead I suspect it was a simple but misguided case of paying with CC to hit a SUB, which will almost certainly end in clawback
He finally did provide an answer to our questions.
https://www.flyertalk.com/forum/36244098-post950.html