@AngryFerret
The phone call is a different case entirely. Sorawo and Toriko was shown acting and thinking logically from in-the-otherside perpective. They only sounded crazy from Kozakura's perpective, which is the out-of-the-otherside perpective. That's why when Sorawo and Toriko heard the recording they were creeped out, because they heard their in-the-otherside voice from the out-of-the-otherside perpective.
In the beach arc, Toriko's stupidity (or maybe insanity) was clearly shown from in-the-otherside perpective. You don't need out-of-the-otherside perpective to know that their leisure vacation was stupid. About Sorawo, she was stupidly weak against Toriko that she stupidly followed Toriko's lead and quickly forgot the danger of the otherside. When Sorawo said, "Have we been taking a leisurely vacation under this?", she only realized that the sky was never a real sky and how stupid they was for having a leisure vacation under that; not that she snapped out of any supernatural state of mind. That means that Sorawo's stupidity was an actual lapse of judgement rather than a temporary supernatural craziness caused by supernatural phenomena.
Kozakura was stupid for quickly refusing Hasshaku-sama's hat without ever researching it (since it turn out to be not a normal hat), especially if she is from an organization that trades in information on the otherside. Sorawo could have collected Kankandara's shards. They could also collected plant samples (biologists would certainly be happy to research that). I think the author just forgot. 😄