Please explain why the prosecution's motion doesn't apply to the prosecution.
One of the exceptions to excluding hearsay is when the statement of one party (in this case, GZ) is used against that party by the other party (in this case, the state):
ADMISSIONS.—A statement that is offered against a party and is:
(a) The party’s own statement in either an individual or a representative capacity;
So the prosecution can use GZ's hearsay statements under an exception that doesn't apply to the defense.
I should clarify that when I said, "The state can use almost anything GZ said," I meant that it would not be excluded because it's hearsay. It could still be inadmissible as irrelevant or more prejudicial than probative.