I have contacted Brian Cosgrove and Trueman; both have confirmed that the episode never existed. This is my message back from the agent of Brian Trueman.
Dear Max
I have been in touch with Brian Trueman who had no recollection of a โmissingโ or non-tx pilot episode. He researched further, and we in touch with Brian Cosgrove. The whole of the first season was written by Brian. There was no pilot made.