When I saw accident in the chapter title and knowing they were headed back to school, the first thought was car accident. They avoided one of those, but got hit by the wrong place, wrong time bad luck. Head wounds bleed profusely regardless of severity, so not much concern there. I hope Devin is hard headed.
We're about to get in a frustrating period for Mac because the hospital won't be sharing much information with him about Devin. He's not able to make any health care decisions either.
And I was only concerned about Preston and Bailey showing up and wondering why Bear wasn't there. Regardless of how this turns out, the dog park will now elicit some bad memories for Mac.