I'm reasonably sure that Ethiopian Airways, & Boeing, are both very glad that Heathrow Fire Service decided to wait around ready to get stuck in again until it was certain that the fire was out and wouldn't be re-igniting any time soon.
How many firemen does it take to check that a fire they put out stays out?
Apparently the heathrow firedept think the answer is 80 firemen and 12 firetrucks.
Not very confident with the expertise or abilitys by the looks.
Normal people would think 1 (if any) with a hand extinguisher might actually suffice, although being right next to the fire station, in a remote area away from the runways/terminals wouldn't impact that decision at all either.