The aircraft could leave Heathrow with Flight Crew and fire watchers
Why would BA want to position crew home, if they are just going to strike? It would cause chaos afterwards as there would be no crew downroute to operate home. Sure they may want to bring crew back from high allowance places, but why bother bring a crew back from Bombay. Leave them there for Christmas on pennies a day. The Hotac is all paid in advance so no saving there.