In the first place, intelligence should not be made public and intel officials should not be making public statements or appearing in public. It is unprofessional and appears to be politicization of intelligence.
Secondly, when this is done and no evidence is provided, especially while counter-evidence exists or even plausible counter-argument based on inference, it is prima facie evidence of politicization that can only be refuted by providing evidence.
Intelligence agencies know this, of course. This is not an oversight but rather a deliberate operational choice.
I am just repeating what former US intelligence officers have said.
“Trust, But Don’t Verify”: US Intelligence Agencies and the New Cold War