Late “Saved by the Bell” star Dustin Diamond once pulled a knife on a fellow actor during an on-set argument, a former production assistant claims. “I don’t remember what started it,” former “Saved by the Bell: the New Class” production assistant Scott DeVaney says in the “Hollywood Demons” docuseries episode “After the Bell.”  According to DeVaney, who didn’t name the other actor, during the incident, Diamond shouted, “I could have you fired” at the unnamed fellow cast member. This “led to Dustin pulling out a butterfly knife. It’s a very physically threatening thing,” he claims. Dustin Diamond (pictured in “Saved by the Bell”) allegedly pulled a knife out during an argument with a fellow actor. NBCUniversal via Getty Images Diamond (pictured in 2016) allegedly shouted “I could have you fired” at another actor while drawing a knife.…