void TASK_HANDS_UP(Ped ped, int duration, Ped facingPed, int p3, BOOL p4);
In the scripts, p3 was always -1.
p3 seems to be duration or timeout of turn animation.
Also facingPed can be 0 or -1 so ped will just raise hands up.
This is the server-side RPC native equivalent of the client native TASK_HANDS_UP.