When the thugs do the drive-by shooting at the outdoor pool table, they're driving the car that is actually Steve McGarrett's 1968 Mercury.
The screenwriter seems to have confused the Bushido (samurai) with the ninja (ninjitsu). The Samurai were not a secret society.
After 41 minutes of the show, the phone rings in McGarrett's office. He answers the phone, but it continues to ring for several seconds more.
Ricardo Montalban with Japanese makeup and Spanish accent.