Ok, good point. But the point that I wanted to make is that a software crash wouldn't explain why the lander behaved as if it was on the ground. So it's more p

Ok, good point. But the point that I wanted to make is that a software crash wouldn't explain why the lander behaved as if it was on the ground. So it's more probable that it reached the "on the ground" condition. If that condition was adequately programmed, the chances that some sensor glitch could have triggered it are quite low. So the probability is higher that it was either badly programmed or maybe someone flipped a bit somewhere ..