The first emotion a parent will feel when their child is gravely injured and on life support can vary, fear, grief, anger. But within those first emotions, is always denial. Denial is very difficult to set aside. Even if tests had been run, I do not see a man with the wealth and power of JS accepting that diagnosis so quickly. Denial is what gives us hope in hopeless situations, whether that hope is founded or unfounded.
If ems had to work 25 minutes to restart Max's heart, this means that even if Max was intubated, oxygen was most likely not being delivered to the brain effectively. For all intents and purposes a brain will 'die' within approx. 5-10 minutes, without oxygen. After 25 minutes, most likely with compressions, some blood may have reached Max's brain, but sporadically at best. This means Max would have been brain damaged at best and brain dead upon arrival to the hospital at worst.
What surprises me is that with two parents involved, that the termination of life support would have occurred so quickly. I was saying this early in the threads, but with the timeline of testing taken, I commend JS and DS in their ability to make such a horrifying decision as quickly as they did.
I guess what I am trying to say, is that I don't think the phone call at 12:50 would have relayed a significant change in Max's condition. I think that it could have been an angry phone call, it could have actually been someone else on JS phone, or it could have been a depressed, crying, heartbroken father. I do not think it was to report a change in condition.