Sisko is rescued by Defiant after Defiant received a location or distress call from planet surface. It is said that it was Gul Dukat's signal, that Defiant received.
How it is possible?
Dukat destroyed its own distress-transmitting equipment in the middle of this episode. And since he escaped on-board Federation roundabout, then he must use its communication systems to transmit a location signal. Defiant crew wasn't familiar with events happening on planet's surface. And thus, how did they managed to say, that Dukat signal was used?