That may be true, but the OP's report that the staff member who acknolwedged a cutoff at T-41 rather than T-40 is proof if believed. But, everything which must be proved is subject to being believed.

If OP arrived at T-39, why would anybody bother with whether the cutoff is T-40 or T41?

A simple enough MCOL claim with a common sense telephonic hearing if it proceeds that far.