777 has a takeoff configuration warning system, so unlikely. Far more likely is the pilots simply failed to command sufficient pitch up (higher pitch gives a lower airspeed and higher climb rate [at least in the airspeed and pitch regime we’re talking about here]).
Takeoff configuration warning can be silenced, but is an abort before the 80 knot callout.
Takeoff configuration warning can be silenced, but is an abort before the 80 knot callout.