I hope this diagram will make it easier to visualise the orientation better - the cross at the bottom is the position of waypoint change (WPCHX) and the red line going up the map represents the bearing to Corran; also, a red line follows 035 mag (the course setting as found on the HP's HSI) which goes through the crash site.
It is clearly nonsense to think that after having changed the waypoint to Corran they would have been safe if they had turned onto that heading.
Nav info relative to Corran from where they were was worthless in comparison to the still useful waypoint A - there had to be a reason for their effectively discarding the GPS/Doppler nav system.
