This film erroneously claims several times that Sweetwater opened the 1969 Woodstock Festival. In truth, Sweetwater was the second act on the bill, after actual opener Richie Havens, but they were the first band to play.
The band is shown playing a Love-in in 1967. The PA system is a modern style that didn't exist at the time. Wedge monitor speakers were virtually non-existent. The Shure SM-58 microphone hadn't been introduced yet, though similar Shure microphones were in common usage. Marshall amplifiers were quite rare, expensive and hard to get. A band like Sweetwater would have used Fender, Vox or Standell amps. The microphones used at Woodstock were Shure SM 56 models, not the SM 58 models used in the film.