From sarna.net:
"Masters and Blane travel to the planet of Gibson (within the system) with the JumpShip and their DropShip only detaches in orbit, suggesting their "JumpShip" was in fact a WarShip."
Of course, the only thing this actually 'suggests' is that Cristopher Kubasik was not entirely clear on how JumpShips and DropShips are supposed to work in the BT universe. But since each and every 'officially' written word on the BT universe is 'canon' and must thus conform to a fictional 'reality', it surely makes more sense to propose an outlandish in-universe explanation for what obviously was a simple goof.