This is a mistaken assumption. Remember that in the very first moments of flight, it is critical that the missile is directly in front of the helicopter, so that the seeker on the missile's rear can pick up the guidance laser being emitted from the Ka-50. Therefore, even a few meters of lateral drift early on will cause the missile to lose guidance and go ballistic. Hence, the aim point is adjusted to give the missile the lateral boost that it needs in order to stay directly in front of the helicopter on its way to the target. All this, of course, is just how I understand it, and I might be completely wrong about it :).