Upon seeing Jod use the Force, Wim is convinced he has to be a Jedi and therefore a trustworthy person who will help them. With how much Wim seems to know about the Jedi and the Force he should know that not everyone who can use the Force is a Jedi or even a good person. After all the story books he was reading showed battles between Jedi and Sith, so he should be just as aware of the Dark Side of the Force and those that practice it as he is of the Jedi and the Light Side.