I saw this post and thought of the opposite situation. https://www.tumblr.com/hugsandchaos/743390512031088640

Jack and Maddie get to know a ghost and realize their theories aren't always correct, and that some ghosts are actually not evil.

...And Danny's pulling at his hair because no actually that ghost is 100% evil and is just being very manipulative to them, and their theories were correct in this particular case. But he can't tell them that! D: ...So he just stays very frustrated and jittery, craving to do something but can't do anything without ruining everything.

(Tell his parents that they were actually right and the ghost is manipulating them despite how careful they are of that type of thing? No, that's a big step backward for accepting Phantom eventually. Fight the evil ghost and take his frustrations out on it? No, that's also a step backward for accepting Phantom. Aaarrgh!!)