Gibson was originally trained to become a medical doctor but shifted to filmmaking, joining the BBC as a scientific documentary filmmaker. He was one of the producers of "Horizon", an acclaimed BBC series that ran for over 15 years. Hailed as the finest science program on British TV, the series featured self-contained documentaries rather than magazine-style compilations and provided an excellent showcase for Gibson's science films, as well as the the model for PBS's "Nova".
Gibson left documentary filmmaking to make his American debut with the disappointing sequel, "Poltergeist II: The Other Side" (1986). He fared better on TV, helming several high-profile TV movies and miniseries including "Murderers Among Us: The Simon Wiesenthal Story" (HBO, 1989) and "Drug Wars: The Camarena Story" (NBC, 1990).