
Did You See the Sun Rise? - S3-E1
Revealing mistake: Going through the database with Lieutenant Maggie Poole, Magnum spots finally Ivan's picture. This involuntary puts a rather hilarious twist to one of the most famous and dramatic endings of a TV episode, since that picture from the military intelligence database is exactly from the 'future', aka the ending of the episode; Ivan is wearing the same black suit and tie (pretty weird already with the setting) that he will wear in the ending, and is even in front of the same tree leaf by leaf. (01:13:30 - 01:34:20)

Did You See the Sun Rise? - S3-E1
Revealing mistake: The actress playing Julie Barbara has short dark hair as is abundantly clear during the lengthy scenes involving her. But for the shot of the explosion, the stuntperson wears a long blonde wig. (00:41:40)
Did You See the Sun Rise? - S3-E1
Revealing mistake: Mac suggest to drive Magnum and Julie to watch the sun rise at the Pali lookout. When Magnum collapses, his watch is at 10 minutes to 2. In April (Queen's birthday), the sun rises in Hawaii around 6, surely Mac did not plan to drive them around for 4 hours. (00:42:00)
Did You See the Sun Rise? - S3-E1
Revealing mistake: MacReynolds is summoned by his superior officer on the observation site. The officer holds his binoculars perfectly still and mostly horizontal, but in the POV shots the visual keeps shifting higher and higher following the missile's trajectory. (00:12:00)
Did You See the Sun Rise? - S3-E1
Revealing mistake: TC's arrival is announced by the loud sound of his helicopter, which makes Higgins' desk comically shake. Fun sight gag, but looks totally phony, since everything in the room, including the plants, is completely still. (00:09:00)