The person in question has already written a response to the open letter: https://twitter.com/WholeMarsBlog/status/1558122848601812993
I'm actually not expecting the Tesla to run over the child (because either it will stop, or the driver will intervene and slam on the brakes or avoid the child). But it also gives me 100% confidence that this person is the exact wrong person to perform any scientific test of the system to even remotely validate its safety.