I'll go along with the inconsistency thing - and I used to travel position internationally almost exclusively. More than once when traveling as a normal full fare passenger I've had CBP question what I do given the quantity and variety of stamps in my passport. Subsequently several of the agents have told me to use the crew line next time to expedite things for myself, "just show your badge."

In turn I've had a one or two agents in the crew line question why I'm using the crew line when I'm not working. "Well, the last time I was through (last month), one of your fellow agents told me to."

Always seemed to satisfy them, and hence my badge was available when I went through.