I concur that "damning" isn't a curse word With this context, but just usually means "bringing about condemnation" and so is not really inappropriate in alone in formal writing. I have certainly heard about "quite possibly the most damning evidence", normally in reference to evidence of a serious crime, and https://jaidenqjdvc.blue-blogs.com/45365568/getting-my-case-study-solution-support-to-work