Dan Tobin plays Dickens in this episode. He would later become a regular for the ninth and final season as Terence Clay, restaurateur.
In addition to playing a bartender who speaks and gets billing, Don Anderson appears as a passerby outside the courtroom. As Mason and Della discuss things, Anderson passes them twice, once apparently coming from the courtroom and once going toward it.
Don Anderson appears in 129 Perry Mason episodes. Almost always in background with no lines or a closing credit. Here he gets a line and credit as bartender. One of only 3 credits.