I posted a similar question a few months back, and the general consensus was that a good fully bonded soft point, and shot placement was very key. People posted their mixed experiences using 5.56/.223 ammo.
As for this video, we don't know what he was shooting, or where is shots were ending up, you're right, at the range, using what looks like to be an acog, his shots may have been going low. In fact, in the video, it looks like hes hitting it in the lower jaw, rather than straight to the noggin.
This video also might just be pointing out how damn tough boars can be. Its actually a good example when remembering what takes a person out of the fight. A person can live and keep fighting for up to 30 seconds even after being shot in the heart. You have to make sure you always put enough rounds into whatever you are shooting, and put them in the right places.