You know how the old saying goes, "if you want something done, you have to do it yourself." I got tired of waiting so decided to tow the Starball myself. At that point the Vagrant communicates that the ship is in tow and that it is heading back to Starpath. I decided to follow it but only got as far as the Orion station in Centris. Nevertheless, the mission was a success and I was awarded the xp. I think that as long as the ship is in tow and out of the Arima system when the timer runs out then the mission will be a success.
AzureSun