They must have known. I haven’t worked with NNs for a few years but I don’t believe the methodology has changed where you would stop testing it over different s

They must have known. I haven’t worked with NNs for a few years but I don’t believe the methodology has changed where you would stop testing it over different sets of training data. Barriers are a pretty big part of driving on roads and highways and the only reason it would have been unknowingly reduced would be if they just weren’t testing the NN against data with them.