My Dad's Heart Was Working At 30 Per Cent But

My dad's heart was working at 30 per cent but was released from the hospital as he could walk, talk, eat and go to the bathroom. He looked like he was improving. He was home four days and then passed in his sleep. Would they let him go home if he had only thirty per cent function? My family is accusing me of not sharing this information. I did not think it was necessary as he had a do not resuscitate and he looked liked he was getting better.