This or another source like it could be the basis for his statement.

Critical race theory is repackaged Marxism | Opinion

There is some factual information and then the quantum leap to say CRT is wholly derived from this. There is some truth in what he is saying although CRT is vastly different from CLS which was an offshoot of a Marxist based theory. Where the writer loses me is the claim that CRT is false information. The Communists or anyone else don’t have to lie when the truth will suffice. Systemic racism is embedded in our laws, courts, customs, and systems. Your friend is using a thin tie to Communism to dismiss the truth because he doesn’t want to accept the truth.

critical race theory | Definition, Principles, & Facts