from flight aware for that flight:
Code:
Time Latitude Longitude Course Direction KTS MPH feet Rate Location/Type
Fri 11:02:00 AM 46.0476 161.5436 56° Northeast Level FlightAware Approximate
Fri 11:02:43 AM 36.0833 167.4500 92° East 549 632 32,000 Level Oakland Oceanic
The northern route was probably the planned route and for some reason it took a southern route. It certainly didn't fly between (46.0476,161.5436) to (36.0833,167.4500) in 43 seconds.
The southern route is longer so they had to stop at ORD for fuel is my guess.