He Lokomaika'i Ka Manu O Kaiona - S8-E20
Visible crew/equipment: You can see a crew member below Junior while he is trying to climb the side of a cliff. (00:18:30)
Lehu a Lehu - S6-E2
Visible crew/equipment: Danny is supposed to be looking for the suspect in the woods by himself and you can see another person on the top right hand side of the frame. The crew member looks as if he knows he is in the way and slowly backs away. (00:35:15)
Visible crew/equipment: When the gunman tries to flee in the ambulance Jerry rams the truck into the vehicle to prevent his escape, and when Captain Grover pulls the gunman out of the ambulance, we can see the boom pole/mic's reflection moving on the windshield.
Visible crew/equipment: When showcasing the empty road as well as Danny's Camaro taking a sharp left for an action scene, there is a camera dead center in the road, and they drive right behind it. (00:28:59)
Ihea 'oe i ka wa a ka ua e loku ana? - S10-E12
Visible crew/equipment: McGarrett and Magnum are working together in this crossover show. They leave a suspect's house and before the scene changes they are outside, and through the door windows you can see a crew member through the glass moving right to left. This is supposed to be an empty house. (00:19:00)
Chosen answer: They are Junior's SEAL buddies.