744drv,
I was wondering the same. In NAM freighter ops, an FO will sometimes burn out prior to the end of the second sector (MIA-IAH-ANC and JFK-ORD-ANC) and "rides" the rest of the way but is still part of the operating crew and credited accordingly. So, I think this is not freighter PXing. That said, the pattern still lacks flexibility. Why use four crew this way when it would be so much better, and cheaper creditwise, to put crew on KA to/from HAN. It seems ridiculous.