Chest, head or a bit both, like this case, it's completely irrelevant because Myers didn't give Armia any chance to protect himself. The situation was completely out of Armia's control, which body part he receives the hit and where his head lands after the contact(this is where Armia got very lucky). Armia's body position and angle was 100% natural while battling with two players.
Grossly irresponsible and indifferent actions from both Myers and the DOPS. The bolded part is the most crucial, and the DOPS ignored it completely.
Such a simple minded pov. I mean, if breathing suddenly wouldn't be an autonomous function, none of the dops team would be able to figure it out.