I would say that’s not actually at all a relevant question, but a form of whataboutism, since this is looking at just driverless programs and comparing how they are with themselves, and what problems with programming and training models could result in that difference.
The crucial point in autonomous car adaption ought to be whether they are better than humans or not. So if they hit fewer children than human drivers do, they're better, even if they were a further 20% better at avoiding adults.