"not vice versa" is a correct and usable phrase in written English. It can be used when a statement is being reversed in order to provide a different perspective. For example: "It was believed that humans caused global warming; however, it is now understood that global warming has caused changes in human behavior, not vice versa.".
"Though not vice versa, eh, Thomas".
We'd be hiring him, not vice versa.
Renewables have to compete with nuclear, if not vice versa.
(The audience is foreign to Marie, not vice versa).
I was on their territory, not vice versa.
"The temperature appears to drive CO2, not vice versa.
We can serve the cause, not vice versa".
Being a terminologist, I care about word choice. Ludwig simply helps me pick the best words for any translation. Five stars!
Maria Pia Montoro
Terminologist and Q/A Analyst @ Translation Centre for the Bodies of the European Union