When the police pick up Alia, she gets into a 1971 Chevrolet Bel Air. When they arrive at Five-O headquarters, she gets out of a 1970 Ford Galaxie.
Mr. Hanolo scolds Koa when he damages the pool table, but didn't say anything when Koa cut the tip off the pool cue moments before, despite the fact he was looking directly at him.
Near the beginning, as an undercover police officer is surreptitiously taking photographs of Rono Vidalgo (Erik Estrada), the initial setup shows him watching Vidalgo's parked car from in front of the vehicle. Then the perspective changes to a view from behind Vidalgo's car as Vidalgo and Alia Kelly (Irene Tsu) enter the parked car, doing a freeze frame to black and white to simulate a photo being taken, even though the photographer has not moved. Then the shot changes again, and the photographer is once again observing the two of them getting into the parked car from in front of the vehicle.
When the car with the bomb explodes the interior of the car it crashed into also explodes and bursts into flames. Since there were no explosives in the parked car, the gas tank would be the only part to explode, not the interior, where the flames would have to spread to, but the interior would not explode nor would flames instantaneously spring up.
McGarretts plane is shown landing on Runway 13 in Honolulu. There is no Runway 13 at Honolulu airport.
The twin rotor helicopter that landed on the church grounds sounded like a piston driven Bell 47. The sound should have been much different these have a turbine engine and the multiple rotors make a far different sound.
About the 8 minute mark, a little after, McGarret opens the door out of his office and the close up of the door shows that the keyhole is blocked by the door itself. There is no hole.
The Priest tells Hidalgo he is no longer welcome, but later performs a marriage ceremony for him, smiling and happy the entire time.