I can see plenty of reasons to change behavior for the test. But that's not the question. The question is why infer you are being tested through the ECU inputs?

I can see plenty of reasons to change behavior for the test. But that's not the question. The question is why infer you are being tested through the ECU inputs? Setting a flag manually seems like a much better solution for all those objectives versus a possibly unreliable inference from speed and other data.