"What to Know
Eighty-six is slang meaning "to throw out," "to get rid of," or "to refuse service to." It comes from 1930s soda-counter slang meaning that an item was sold out. There is varying anecdotal evidence about why the term eighty-six was used, but the most common theory is that it is rhyming slang for nix."
Slang for murder,comes from the California penal code i believe.
We should probably figure out where it comes from, otherwise we could be wrong,
Though the story does reminding me of this...
https://www.youtube.com/watch?v=7s1th5omaLg
Google up the slang dictionary and even Wikipedia . It means kill,expicaly in this context.
Well I found this on Merriam Webster
"What to Know Eighty-six is slang meaning "to throw out," "to get rid of," or "to refuse service to." It comes from 1930s soda-counter slang meaning that an item was sold out. There is varying anecdotal evidence about why the term eighty-six was used, but the most common theory is that it is rhyming slang for nix."
merriam-webster.com/wordplay/eighty-six-meaning-origin
So I agree with your statement.
In a few days I am going to be with family who are sheep. So if it comes up I need to back up my points.
https://en.m.wikipedia.org/wiki/86_(term)
Last paragraph.