Visible crew/equipment: The last time we see George in California he is running down the road. When the camera moves up you can see the shadow of the camera man and camera crane on the ground as clear as day.
Visible crew/equipment: When George is running back to the jungle from the city, he journeys in a boat along a river. Unfortunately, you can see the wake made by the camera boat in front of the boat in which George is travelling.
Answer: There's certainly no listing for him on the IMDb, which is generally good with uncredited appearances. Farrell was still working in the UK and Ireland at the time of the film, which was entirely US shot, and didn't become involved in Hollywood productions until about the year 2000, three years after GOTJ came out, which would seem to make it extremely unlikely that he appeared in it.