An editing oversight inadvertently transformed Sean Murray’s Timothy McGee from a guest appearance into one of NCIS’s longest-running characters. Originally intended for just one episode, McGee’s role was extended after a small mistake required his character to return and collaborate with Michael Weatherly’s Anthony “Tony” DiNozzo.
Despite initially being slated as a guest, McGee’s return wasn’t apparent until he officially joined the NCIS cast at the start of season 2. Over the years, Murray has developed McGee into one of the franchise’s most significant and integral characters.