It's believed that this diver panicked because he found himself alone.
A trained and experienced solo diver would not panic if he found himself alone, therefore he would not have been in that predicament.
Your statement is about as ludicrous as saying what would I do if I found myself on the moon with no way to get home.
As a trained and experienced solo diver, I will disagree with the above statement.
Diving solo is a planned event. When you do it, you go into the dive with a particular mindset.
Buddy separation is an unplanned event. Even though, physically, you find yourself diving solo, EVEN IF YOU ARE A TRAINED AND EXPERIENCED SOLO DIVER you are not solo diving. You have a buddy out there somewhere that you don't know what happened to. It takes your mind off your dive. It causes you to second-guess yourself and focus on things you may not be prepared to focus on. Depending on the buddy, it might lead anywhere from mild irritation to a serious case of stress ... and the further up the stress ladder it takes you, the more likely you will be to do something that will eventually lead to an accident.
Diving is at least 50% mental ... taking your mind out of the game is the best way in the world to put yourself onto that chain of events that eventually leads to an accident.
This situation has nothing to do with solo diving ... or even with being trained and experienced as a solo diver. It has everything to do with what happens to a diver's mentality when the unexpected happens. Everyone's different ... some people have an easier time staying calm in a crisis than others. Personality has as much to do with that as training and experience.
So unless you know the person involved, you have no way of knowing how they will respond. And in a lot of cases, you won't know how a diver will respond until they find themselves in the situation that causes the stress.
And FWIW - it doesn't take panic to lead to an accident. All it takes is enough stress to take your mind off what you're supposed to be paying attention to ... underwater, stress is NOT your friend ...
... Bob (Grateful Diver)