Continuity mistake: While Magnum is at Erin's place he watches Erin's videotapes, and the TV set he uses changes style between wide shots and the TV's closeups, during the requisite scenes. (00:21:25)
Continuity mistake: While Magnum is at Erin's place, when he pops in the videotape of "acting class winter 1974" the VHS machine atop the TV is entirely silver on its top in this and a following closeup (also note there's black tape covering the machine's brand name). However, in other shots the machine is black and silver on top, which is even more noticeable in another closeup after Magnum shows David the videotape of Erin with the shotgun. (00:22:05 - 00:25:45)
Continuity mistake: Rick leads Magnum to David Norman that is drinking heavily at the club. When he shouts "Nurse" at the beginning, a woman in a pink bikini holding a straw hat moves across the area to get to railing. That same woman walks in and "just reaches the railing" about 4 times during the remainder of the scene. (00:10:10)