After Sarah and Sheridan have their conversation in the corridor, the jammer is left in place against the wall. Sarah had forgotten to retrieve it.
Throughout the story, the fugitive is called "Dr. Jacobs". When they use the station's scanners to search for him, the computer screen refers to him as "Jacoby".
Ivanova says the area Sheridan called downtown had been sealed off since the station was built. Sheridan said the security men would have to burn through several bulkheads to get in. The doctor could not possibly be hiding in there since it is sealed, yet the security men men search there.
Since neither Sarah nor Sheridan turn off the jamming device immediately after their clandestine conversation, it would be impossible for Sheridan to call Garibaldi on the link.