Hell or high water and potentially fatal damage to his ship--dust storms tended to clog exhaust vents, thruster ports, and gun barrels, not to mention not being able to see an inch past the cockpit window to fly out anyway. The flight restriction meant that until the storm blew over none of the beacons would lead incoming starships to this particular port city, nor would they offer a clear lane out into orbit.
Randy was of course welcome to try; after all it wasn't like there were a line of picket ships to prevent unauthorized approaches or departures, but the dock workers at least in this city did a good job of logging every ship that set down in Gate City and forwarding each day's logs to the nearest military facility.
Besides that, smart pirates set traps in deep space and waited for a catch, not try to break into locked ships on planets with a military presence. All part of Terry's strategy, actually. By maintaining a regular and legitimate appearance right under the army's nose, he could operate without suspicion.
Back at the Inferno, while security teams were arriving to take Randy into custody, Terry himself was finalizing a deal with an army officer who obviously thought better of using official resources to get the job done. The job of smuggling illicit goods onto space stations along with legitimate cargo was something that the Osiris handled, though not often, and never without adequate cause.