The son was told his father had been examined. Maybe he thought his father was receiving treatment when in reality he wasn't.
The sentence you quoted is the large part of the problem with this article. Was Dr. Applebaum present for this? How else would he know that his father was not examined? This is not made clear. If he was there, he is a physician, and should have done something. Acute abdomen is not a diagnosis, it is a complaint. It can be caused by numerous things including pancreatitis, peritonitis, or appendicitis. These things will kill you, but it could also be severe intestinal cramps from bean burritos and beer.
A physical exam includes looking for fever and diminshed mental state (signs of infection), rebound tenderness, localized pain at the site of the appendix, and tight muscle in the area of the appendix. Dr. Applebaum can’t order the blood tests that confirm the infections, but all that takes is an order from a physician, a phlebotomist and a lab. In truth, the nurse could do the exam and the physician is not needed until the lab report comes back. Even then, most nursing students could look at the exam and the blood tests and see what is happening.
Now if they didn’t order the blood tests, they are beyond negligent. They would have no idea if Mr. Applebaum is about to develop a systemic infection and rapidly die, which is what happened. The physician is negligent, but so is the charge nurse because the nurse should have found another physician to sign off on the tests. You can also legitimately blame the ER physician because he is supposed to be aware of what happens in his ER. And Dr. Applebaum, if present, could have put his father in a wheelchair, had a private ambulance meet them at the door, and sent dad to another hospital immediately if this is what was going on.
The story is missing some very important details.