People can mistake relief at being believed for proof that their whole account is complete.

Being believed is an enormous relief, and relief can quietly close an inquiry. After a hard account, the question you were most afraid of, whether anyone would take you seriously, gets answered, and that answer can feel like a verdict on everything else you said. Those are separate things. Someone can be entirely right about what happened and still be missing a piece they had no way of seeing.

Let being believed settle first, because that part matters. Later, when it is less raw, you can look again at whatever you are least sure of without it costing you the belief.