I agree that "damning" isn't a curse phrase in this context, but simply means "bringing about condemnation" and so isn't inappropriate in alone in official writing. I've definitely heard about "the most damning proof", normally in reference to evidence of a serious crime, and didn't presume they were referring to https://mariowodvx.wssblogs.com/37526657/the-definitive-guide-to-mba-case-study-solution