In the scene where Jack is being rescued from the tube playground, the Fire Department would never use a chainsaw in that circumstance. Jack was in no life-threatening distress (his back simply went out and he could barely move) so the chainsaw would be far riskier (and, frankly, unnecessary) than simply using wrenches to disassemble one or more sections until they could free him.
Around 14:48 when the producer (Played by Alex Rocco) walks into the restaurant, you can briefly see the top of the stage.