MU3001A
BA SOP is for the P1 for the sector (Captain or FO) to hand over control before TOD to the P2. The P2 then flies the aircraft until the P1 becomes visual and takes control, the theory is that at DA the P1 is looking out, sees the runway and takes control for the landing. If operating with the weather above DA this handover of control usually takes place shortly after 1000RA. In this case it appears that the First Officer was the P1 for the sector and the timing of the handover was not unusual, PEK-130 miles before LHR is quite a long leg.