At the end of act three, McGarrett and Danno tail Cavell in their car. Cavell stops at a stoplight and looks in his rear view mirror. McGarrett and Danno appear - looking like they're in the back seat. What's more, the shot shows McGarrett and Danno still moving, while the view out of Cavell's front windshield shows that he's stopped - which gives the impression that McGarrett and Danno should be plowing right into him!
The official syndication number for this episode is 7307.