Implementing "melee push" with doknockback?

[Furniture]

Luckily, there is a function where this is taken care of:

void Mob::DoKnockback(Mob *caster, float pushback, uint32 pushup)
{
	if(IsClient())
	{
		CastToClient()->SetKnockBackExemption(true);

		EQApplicationPacket* outapp_push = new EQApplicationPacket(OP_ClientUpdate, sizeof(PlayerPositionUpdateServer_Struct));
		PlayerPositionUpdateServer_Struct* spu = (PlayerPositionUpdateServer_Struct*)outapp_push->pBuffer;

		double look_heading = caster->CalculateHeadingToTarget(GetX(), GetY());
		look_heading /= 256;
		look_heading *= 360;
		if(look_heading > 360)
			look_heading -= 360;

		//x and y are crossed mkay
		double new_x = pushback * sin(double(look_heading * 3.141592 / 180.0));
		double new_y = pushback * cos(double(look_heading * 3.141592 / 180.0));


		spu->spawn_id	= GetID();
		spu->x_pos		= FloatToEQ19(GetX());
		spu->y_pos		= FloatToEQ19(GetY());
		spu->z_pos		= FloatToEQ19(GetZ());
		spu->delta_x	= NewFloatToEQ13(static_cast<float>(new_x));
		spu->delta_y	= NewFloatToEQ13(static_cast<float>(new_y));
		spu->delta_z	= NewFloatToEQ13(static_cast<float>(pushup));
		spu->heading	= FloatToEQ19(GetHeading());
		spu->padding0002	=0;
		spu->padding0006	=7;
		spu->padding0014	=0x7f;
		spu->padding0018	=0x5df27;
		spu->animation = 0;
		spu->delta_heading = NewFloatToEQ13(0);
		outapp_push->priority = 6;
		entity_list.QueueClients(this, outapp_push, true);
		CastToClient()->FastQueuePacket(&outapp_push);
	}
}

The problem isnt that it isnt getting hit and pushed in the right angle, but when a player is fleeing and is hit by a mob, they are "summoned" a little bit backward toward the mob. When a player is going toe to toe with a mob everything works as intended.