Might the weather be a possibility? I don't know whats its been like over the NATS but its been quite stormy here (
DUB) over the past few days with westerly winds blowing across the country. Add to that holding over
JFK and any number of other scenarios that can occur.
DUB-
JFK can quickly turn from 7hrs to 8 1/2 even 9hrs if just a couple of things line up right... or wrong in this case.