2 things.
1) I cannot comment on the 'bare bones' report you gave us in post #1 - we do not have enough information on the situation they were in.
2) Re GPS - I know not. I suspect that since GPS is primarily only giving position as far as I know (possibly heading, but not sure) I do not think it will feed into the FMC to enable NAV capability. Providing the POS page can be accessed, however, you will always have a lat and long available, but I am not sure I or most others could navigate too easily with that! Back to a plotting chart and a very sharp pencil I feel.
