Yes, a soundtrack is the recorded score from a MOVIE and an OCR or cast recording is the recorded score from a stage musical.
But, I wonder sometimes over how much time we spend on these stupid little issues. Mention it and move on. What's the big deal if someone uses the term correctly or incorrectly and you've corrected them twenty times. They either GOT it or they didn't GOT it...you know what I mean?
"Life is a lesson in humility"