Calvin Boone breaks into Perry's office by climbing around a partition on the balcony between Perry's office and the office next door. That's the same way Helen Bynum, a.k.a. Virginia Colfax, got into Perry's office in The Case of the Dubious Bridegroom (1959).
During several scenes, it's clear that Raymond Burr had a cold/illness, as his voice sounds very different.
William Talman appears here since this episode was filmed before he was fired.