Ex up...you are right it was a total loss of indicated oil....there was however enough oil to pressurise and cool the bearings and no pressure loss at all. We need a Trent / RB 211 specialist to explain what does sound counter intuitive. Any subsequent change in oil pressure requires an immediate divert....in the BA case the 787 Dumped indicated oil over St Johns and continued ( being monitored very closely) to Houston with no change in pressure or temperature boroscoped in Texas....no damage.