User blog comment:TheMG/New Metroid Answers Wiki/@comment-6008104-20100525220200

I meant due to the weird circumstances of its usage... I am not sure if the game actually checks that you obtained the Phazon Beam if you are in one of the pools. Since the developers OBVIOUSLY didn't expect people to skip items (as indicated by the Player's choice version), they might have lazily made the game only check if you are in a pool. That is why I asked the question.

I'll check this myself.