Porter (wearing cream colored pants and a blue Hawaiian shirt) is shown filming one of the fires, then turning his camera onto Stokely and following him thereafter with the lens. Later, when he's showing "his" movie footage of Stokely, Porter is in his own supposed shot because it is merely part of the earlier scene from the actual episode itself, posing as a home movie.
In the beginning when Danno enters the church the pattern on his tie changes between shots.
Fire trucks heading to Kleppers are red. After the fire is put out the fire trucks leaving the scene are yellow.
When the security guard is walking out of the warehouse on fire, it's clear it's a stuntman wearing flame-retardant gear instead of the uniform.
After Ray's car is searched and stolen company property is discovered, he is fired and physically removed from the premises. The parking lot gate is closed behind him. A private company should not be legally allowed to retain a vehicle (which is not to say that they wouldn't). Only the police can do that. Later that day, one of the people framing him calls about a job offer and Ray is obliged to accept a ride.
On his way to detention from McGarrett's office, Ray notices a newspaper which has a picture of Klepper and his wife without her blonde wig on page one. There is no logical reason for their photographs to be prominently featured.
From the films he makes, Porter notices Ray Stokely at several of the fires. How Porter is capable of uncovering Stokely's trouble background is problematic. Because when McGarrett seeks such information from Dr. Bishop, he must obtain a court order.
The end of the show is unrealistic in terms of logistics. While Porter is on his way to the airport, McGarrett manages to set up a bogus fire knowing Porter could not resist the temptation to have a glimpse. It is implausible that McGarrett would be able to determine the route Porter would drive to the airport.