Depends on what he means by the earth being that old.
SINCE it was void and without form or since the first atoms collected together in some sort of tangible form?
I don’t think much of anyone has much of a clue about super ancient history regarding this sphere or any other. The Scriptures are not overly clear. And science is guessing about as much as folks trying to read all manner of things into Scripture about it.
It’s all wholesale inference, speculation, bias, dogma, extrapolation etc.
Pretty flimsy stuff to built anything of substance on.
Well, he is an anthropological Christian scholar who teaches at either Boston College or Boston University. I’m sure he’s researched this as much as anyone can. None of us really knows the answer.