According to Tony Moon in Down by the Jetty: The Dr. Feelgood Story
, "It Wasn't Me" started as a backing track to which Nick Lowe put lyrics.
The album wasn't produced by Lowe but by Richard Gottehrer, although Lowe was hanging around the studio at the time. The music is credited to guitarist John Mayo. The song runs to 3 minutes 6 seconds, and is the eighth track on the October 1978 Private Practice
album. The title begs the question, if it wasn't you, who was it?