Symptom:
If a user passes in an invalid query parameter where the expected response is just a single instance and not in the format of a list, the query check is not enforced and the invalid query parameter is just ignored. The expected behavior, and the behavior seen when the response is in the format of a list, is that an exception is returned to the client when an invalid client is passed in.

Conditions:
This occurs when an invalid query parameter is passed is for a response that can only be null or a single instance. For these APIs, the only current valid query parameter is "_derived".