If they support current Big Bang theory, they're all creationist.
By the same reasoning, if a schizophrenic claims the sky is blue and we all agree with him, that makes us schizophrenic too.
The deeply flawed reasoning is implying that, because we agree with the observations of a creationist astronomer on the big bang, we are also creationists.
It's believing that the value of time T is such that it conflicts with innumerable results from geology, physics, and astronomy that does.