On the final episode of “Late Night With David Letterman” in May, the talk-show host flashed back to one of the most bizarre incidents of his career. A long-haired, jittery Crispin Glover, then promoting the 1987 drama “River’s Edge,” strode onstage in striped bell-bottom pants and platform shoes, and challenged Letterman to an arm-wrestling match. “I’m strong. I can kick!” Glover shouted, baring a bicep only slightly larger than a flea bite, and fired off a karate kick, which landed inches from Letterman’s head. Letterman cut to commercial, and when he returned, Glover had been escorted to a taxicab. “That is not how I want my life ended, some goofball, some dork from wherever,” Letterman, unamused, told the camera.