DOCSP-46169 Verifier Guardrail Notice (#567)

* DOCSP-46169 Verifier Guardrail Notice

Author: kennethdyer

source/includes/fact-verification.rst

@@ -2,5 +2,12 @@
 Before transferring your application load from the source cluster to the
 destination, check your data to ensure that the sync was successful.
 
+.. note::
+
+   If ``mongosync`` stops during commit, before the
+   :ref:`/progress <c2c-api-progress>` endpoint reports
+   ``canWrite: true``, you must restart the entire migration to
+   ensure that it's verified.
+
 For more information, see :ref:`c2c-verification`.