Kris was a janitor at the studio and would show Cash his songs that was before Sunday Morning Coming Down. That would have been late 60's I guess in Cash wilder days.
I can't find that video either but I have seen the interview and it was Cash telling the story. They didn't meet in a bar but it was about him. The Junkie and the Juicehead was one Kris obviously did about himself.
There is or rather used to be on Youtube a longer version of this which has Johnny Cash explaining To Beat The Devil https://www.youtube.com/watch?v=8zXirzWc0mM&list=RD8zXirzWc0mM For some reason some of Kristofferson’s videos have been pulled and other ones remain.