Working for an outfit who are very keen that the relief pilot is "involved" I'd have to say that I am in some agreement with the above, however looking back at the OP's bullet point 3
Relief pilot calls out ''Alarm'' the PNF calls out ''go-around'', the PF responds by applying full power to initiate the go-around, which disconnected the Auto-Throttle.
I'd suggest the die was cast once the
PNF had made their call...