In Dusk's Dawn Donut doesn't notice anything suspicious about the antagonist after he claims that he's "obviously cured."
Coach Z on Homestar Runner. It seems that he only keeps his "more than two praeblams" (other than his butt fixation) for one episode. The whole cast plays dodgeball with the proverbial Idiot Ball.
The titular character IS an Idiot Ball, which is really almost the point of any short with him in it.
Really, everybody's held the idiot ball at some point or another. Even the more saner members of the cast (I.E. Strong Bad, Bubs, Marzipan) can go from Only Sane Man to complete looney in a matter of seconds. Even Strong Sad, probably the only consistently sane man, has his moments of utter craziness.
RWBY: Raven planned to steal the Relic for her tribe and use it to keep Salem away from them. In "Haven's Fate", Yang points out just how poorly thought out her plan is. If Salem was willing to come after her when she thought Raven was only harboring the Spring Maiden, then she would definitely hunt her with everything at her disposal upon learning she had one of the Relics Salem's after. The look on Raven's face indicates that she didn't consider that possibility, and the fact that she lets Yang take the Relic indicates that she agrees with her.