[unspun]

If a maverick historian came along and tried to claim that the Roman Empire never existed, or that the United States of America existed before England did, would academic historians be under any obligation to give attention to his work?

Sorry, but I don't see that analogy as quite apt. It seems that Mitra, as wild and inaccurate as his theorizing may have been, did serve to point out an inaccuracy in then-current "belief" by the scientific community.

[Physicist]

It seems that Mitra, as wild and inaccurate as his theorizing may have been, did serve to point out an inaccuracy in then-current "belief" by the scientific community.

Not even remotely. Mitra insists that black holes are impossible. Then Hawking changes his opinion on a very subtle theoretical issue regarding black holes--a change which, I might add, had been urged on him for years by Kip Thorne, who by any standard is a mainstream physicist--and Mitra claims vindication? Preposterous.