So actual grounds for termination should be ignored, depending on who uncovered them?
Not for this case specifically, just in general.
Not "who uncovered" but "how it was uncovered".
You shouldn't eat from a poisonous tree.
See: https://en.wikipedia.org/wiki/Fruit_of_the_poisonous_tree
In a nutshell: you don't want to encourage the police to break the law at any cost. Even it produces evidence.
Nintendo did the opposite: they encouraged them to go even further with doxing.