If you take "partially fail of regulation" to mean stuff like "a defeat device switching emissions controls off if more than two wheels are spinning is not lega

If you take "partially fail of regulation" to mean stuff like "a defeat device switching emissions controls off if more than two wheels are spinning is not legally a defeat device", then sure. Otherwise, there are of course issues with testing methodology. At the same time, pretty much the entire car industry used defeat devices on their diesel cars.