Big Lipped Alligator Moment: Two here: the first is when Walt and Ja Rahr turn the channel on a motel TV, and it starts attacking. Another happens when two silverfish are chasing Walt's car shooting missiles at it. None of these events are referenced at all later in the film.
Fight Scene Failure: In-universe. Walt's auditioning for an action movie, when all of a sudden robots start attacking him and a prop explodes. It takes a second after the explosion for Walt to get launched.