Critical Film Studies - S2-E19
Trivia: Abed mentions being an extra on the show "Cougar Town," and inadvertently soiling his pants out of nervousness. Abed actor Danny Pudi actually did appear in a cameo in the season two finale of "Cougar Town", which aired two months later. Although his cameo isn't quite as described in "Community", Pudi is visible in the background of one scene in-character as "Abed", and attention is drawn to him when he dramatically runs away at the end of the scene. (Likely because he soiled himself as described in "Community.").
Answer: His attempt to "kill" Jeff was to roll at him as an iPad on a stick. He knew it wouldn't work, but it played to the story that he was a killer as he knew Jeff would tell people about it, or attempt to retaliate for it.