GGV,
Yes, I agree. I would go further and say ".....that all, or the majority, of US carriers leaving LAX fail to meet some aspect of the FARs" on occasion.
Take a look at the FAA enforcement database; it is full of household names. Of course that doesn't mean to say it's right, and definitely doesn't excuse people from not being au-fait with the regulations of the state they are flying in.
I guess the issue in my head is, if they had loaded fuel as calculated by 14CFR121.645, would they have made London, landing with fuel reserves greater than that required by the CAA.