it's a pattern with Trump. Deny he did anything wrong, but if something was done wrong, it's someone else's fault, Trump will never own up to his misdeeds or failures.
This sort of thing is more for the benefit of his fans. In their minds, Trump is infallible, but if there is any question that Trump did wrong or did not do what he should have done, then his fans need a scapegoat to blame if there is ever any question. These fans can't respond to any allegation of Trump wrongdoing or failure until they get the official response from their idol.
You would think by now Trump's fans would be wise to his M.O., but they are so enamored with him, they accept anything he says or does without question. No wonder some refer to Trump and his fans as a "cult."