If he knew he had a low pressure tyre - and does the 777 keep track of tyre pressures on all the electronic gizmos, presume it does or how else would he know ? - and had said nothing, and then had a tyre burst, wheel fire maybe, on landing, he would have been soundly criticised for not requesting emergency services standing by, so no problem advising of a potential problem, but priority landing ? That does seem a bit over the top, unless of course the pressure monitoring had indicated that after another few minutes there would be no air left in that tyre, so better to land on a "soft " tyre instead of an "empty" one. Maybe.