Bob Hyatt's fraternity is Chi Beta Sigma, a not-very-sly allusion to the CBS network.
Other than Raymond Burr (of course), the first episode to feature only two credits on the opening titles: Just Barbara Hale and William Hopper.
When Joe is at work, he's wearing a "Manzana Prep" sweatshirt, suggesting he attended the (fictitious) private high school previously seen in The Case of the Decadent Dean (1963).
Barry Atwater had previously appeared in The Case of the Prankish Professor (1963), where he had also played a college professor accused of plagiarism and is murdered.