As the police car pulls up to the Royal Beach Hotel, it is obvious when the car is first shown it is not moving and only starts moving forward just after it is in the shot. It is not coming from a long distance, but a mere 3-4 car lengths way.
(At about 5:00) A tracking shot shows a lit window in an office building, presumably meant to be Perry Mason's (following shot). However the building does not have the distinctive balcony outside Perry's office.
H.M. Wynant is listed in the credits as Tony Mario. However, in the courtroom, he is referred to as Mr. Earl (or Errol, as the Closed Caption spells it) by both the DA and Perry Mason.