Sean Tuohy is firing back at Michael Oher ... calling BS on all of the former NFL star's "insulting" allegations -- while insisting he and his family made little money off of the success of "The Blind Side."
The 63-year-old -- who was played by Tim McGraw in the 2009 hit movie -- said he was "devastated" to learn that Oher had accused him and his wife, Leigh Anne, of exploiting him for fame and money in a court filing in Tennessee on Monday morning.