Like brother
ProSpeeder said, there's just no way to tell.
That's why I, personally, am very reluctant to post up "save" stories.
There's simply never any telling why one was not pulled-over. It could be just that the enforcers were after bigger fishes that day. It could be that the particular enforcer you were up against simply felt that you weren't driving dangerously (even though you were speeding). It could even be that his gun threw an error code.
Who knows.
Yes, catching scatter/reflections or up-road beam is definitely possible, and yes, you can "outbrake LIDAR."
But in cases like this, there's no real way to tell of a save, versus just blind luck.