In order to obtain evidence against a suspect, Kono poses as a telephone repairman to gain access to the suspect's garage. McGarrett later treats the evidence as something that could be used to convict the suspect. Even when this episode was made in 1971, however, Five-O would have needed a warrant to obtain the evidence, and merely because Kono was allowed entry because he was pretending to be a telephone repairman would not have prevented the evidence against the suspect from being excluded by the court.
McGarrett informs Dr Southmore that his wife was killed with a .38 caliber Smith & Wesson pistol. Ballistics will reveal the caliber of the pistol, but not the brand. Not unless it is a highly unusual type of bullet, which the .38 fired by the Smith & Wesson and many others is not.
McGarrett shows Dr. Southmore two booking photographs of Harper to identify. But during the booking scene, only one was taken before he collapsed and he was wearing different clothing.
Steve McGarrett is seen not wearing his suit jacket and wearing a shoulder holster on his left side. There is, however, no harness for the holster that wraps around the right arm. The leather harness, holster and gun are simply draped over the left shoulder with nothing to prevent it from falling off. From the back the support strap should be clearly visible. It is clearly not there.
The maid says she looked out the window as the killer's car was driving away, but in the opening scene, the maid hears the first shot walks to the window and looks out just as the robber is removing the gold chain from around the woman's neck. The maid screams, then the woman is shot in the head. The amid saw the robber remove the chain from the woman's neck, and also saw her being shot in the head.