Two major characters are assigned differing first names, respectively, in the credits and dialogue; Mr. Jarech is Eugene/Arthur and Dr. Barnes is George/Philip.
The envelope supposedly containing Dr Barnes' journal is much too thin to hold it.
At 0:14 Della Street says Mary K. Davis's phone number is NOrcross 4211. Los Angeles had 7-digit phone numbers. Perry Mason's number was MAdison 5-1190.
When Perry calls Mary K. Davis, he dials only six numbers.
Dr. Barnes's first name in the closing credits is listed as George and Mason uses the name George once. However, in court, Hamilton Burger refers to him as Dr. Philip Barnes.
Paul tells Perry that Eugene Jarech and Mary K. Davis met for cocktails "yesterday afternoon". Jarech and Davis met at 6 p.m.