“One Marine told us that military history training session was replaced with mandatory training on police brutality, white privilege, and systemic racism. [..] Another servicemember told us that their unit was required to read White Fragility by Robin DiAngelo which claims, and this is a quote, ‘white people raised in Western society are conditioned into a white supremacist world view,'” Cotton added. - https://pjmedia.com/news-and-politics/tyler-o-neil/2021/06/1...

The defense secretary being questioned did not deny these assertions. But the truly motivated will find ways to call this "not evidence" as well. Only 100% incontrovertible proof counts as evidence for assertions they don't like. The bar is, of course, much lower for things they'd like to believe.