The shadows created by the "sunlight" coming through the courtroom windows does not change position during the day, showing that it is not real sunlight.
The pen holder on Perry's desk moves between shots while he is discussing the case with Sarah Werner.
The photo of the man holding the little girl on his lap is a fake. It is obviously a doctored photograph combining two different photos. Proportions of the two are wrong, the contrast in between the two is different, and shadows are not in the same direction.
Burger reads an affidavit for 'Amsterdam, Holland'. Amsterdam is in The Netherlands.
Mr. Van Beers lived right across the hall from the murder victim and certainly must have heard the shot that killed him/her, but this fact is never addressed by either Perry Mason or Hamilton Burger.
During court testimony, Mr Schoenbeck tells Perry that Adolph Van Beers is from Holland, as is he himself. Yet in an earlier scene, Mr Van Beers addresses Virginia Trent as 'Liebchen', which is German. The corresponding Dutch word would be 'Liefje'...