Ah yes. I think the thing with SFO->LAX->LHR->ZRH or SJC->LAX->LHR->ZRH is a married segment thing. The first two flights are (I think) a married segment, which (a) makes them hard to search matrix for by mixed cabin (eg F and J), and (b) makes them hard to search elsewhere by inserting a connection. Made worse by the fact Amex/GBT's new interface doesn't support mixed class bookings and the old one seems ... somewhat cranky.