He is talking about a SAM operator.
Unless I am much mistaken, which is perfectly possible since I know nothing whatsoever about the subject, somebody needs to first find the target to hand to the SAM operator for the killing of the target.
Some kind of wide area radar surveillance needs to first realise that there is a target up there.
Otherwise how does the SAM bloke know roughly where to look?
Those guys might have rather different radars/ interest in undercarriage door shapes.
Since the other stealth aircraft have these doors, we must assume they have a reason. Yes, the drone is a lot smaller than a B2, but it is not that small, and boy is it noisy.