Johndor:

The fuel taken on during that unplanned stop was not just to keep the generator which powers the in-flight entertainment system running.

Westerly headwinds are particularly strong during the winter, and it's not uncommon for aircraft to make unscheduled stops in order to take on added fuel making up for the excess burn reqired in throttling up the engines to compensate for headwind flying (in the interest of trying to keep on schedule, as a matter of fact).

So in one sense, the decision to stop in ANC was "controllable." ... But what was the alternative?