I guess they posted it because they honestly didn't think they had done anything wrong.
Looking at the four clips, the first one, they kept shooting at the van long after it was necessary, but the initial engagement I can't really fault. The second one, might be the guy in the merc ducked, and hit the Caprice. Third one I actually have no problem with. They used a simulator first, when he kept coming, they fired warning shots, and he pulled over and got out of the car. The fourth one certainly looks excessive on the face of it, but what we can't see (Similar to the second case) is if the contractors are giving any visual signals before shooting. (i.e. waving madly).
There's enough in the videos to question and warrant investigation, (plus the whole judgment issue on PR grounds, I guess), but not enough to convict without background knowledge.
NTM