“(But...the captain and crew were going to go oceanic to Japan unable to explain the loss of 6,000 pounds of fuel an hour if they didn’t know exactly what was going on?) “
I cannot imagine they would have...by the time they were near the coast the total fuel lost would have been so big they would have had no choice but to land and check it out. I am under the impression here they were less than halfway to SF, given the initial decision to return to ORD.
Yes, loosing fuel at that rate would have been close to 20,000 lbs by the time they got to SFO.