Miller is obviously not as good as MM, and very likely not as good as FQ, but has had much ill fortune himself including last year, and has had arm pump himself without anyone cutting him much in the way of slack.
He rode a good race and was the best rider on the day. That is my point. You can gainsay many race wins and numerous titles for that matter on the basis of rider ailments if you want to do so, but these are not the concern of any race winner, it is up to the opponents to line up on the grid in a state of sufficient health. As I said MM sustained his injury over riding in pursuit of FQ which Jack didn’t do, and there is no way of knowing whether FQ’s tires or skill/concentration would have held up for the remaining laps with only a 1 second lead regardless of any arm pump issue anyway.
I remember at the time most though it was possible Fabio had overcooked his tires such was the pace he was setting. I believe he likely would have been able to keep the lead and win if not for the arm pump but I very well could be wrong