Ko'olauloa - S1-E6
Continuity mistake: When McGarrett chases the bad guys' Jeep, his Camaro skids through several huge dust clouds. Immediately after each cloud, however, the car is perfectly clean again. This is visible in several of the very rapid shots throughout the chase. After the chase ends, a coating of dirt and mud (which, incidentally, differs from the earlier shots) appears on the Camaro.
Continuity mistake: When Steve and Danny enter Bar 35 it's daylight, and when they leave after no more than a few minutes it's completely dark.
Continuity mistake: During the police chase there are flashing blue lights visible on Chin and Kono's faces during the interior shots, but from the outside of the car only the flashers in the grille are working.
Continuity mistake: When Danny goes to the police station and Grace runs to hug him, her left arm switches from being around his neck to under his arm.
Chosen answer: They are Junior's SEAL buddies.