CHICAGO (AP) — In a departure from normal practice, federal courtroom staff this week did not record a significant hearing that touched on government surveillance methods, and a court official attributed the mistake to workers spooked by U.S. agents sweeping the courtroom for bugging devices.

Gino Agnello, clerk of the U.S. 7th Circuit Court of Appeals in Chicago, told The Associated Press that the failure to record Wednesday’s much-anticipated hearing was a first in his 25 years on the job. As a matter of course, oral arguments at the appeals court are recorded, then promptly posted online.