Funny how some players have shoulders, and some have heads. Cotchin had the opportunity to tackle Shiels, as Shiels had already taken possession, but was intent on hitting Shiels with a forceful bump. Once he had taken that option, Cotchin had to make sure he did not hit the head. He did not take enough care. He hit Shiels on the jaw, and caused a concussion. That is what the medical report SHOULD state, but I have no doubt that the MRP will take the view that initial contact was with the shoulder, and any other contact was incidental.
That is not the view they take when Fyfe, Walters or Darcy are the ones in the gun, but hey, we are paranoid and biased conspiracy theorists ayy? The similar incidents I recall this year that went unpunished were both hits on Walters.