You sound like a safety officer!Using an example here to bring in the element of 'risk'.
A defender under absolutely no pressure is trying to chest a long ball in his own PA. He does so with his arms well wide of his body. He misreads the flight of the ball and the ball clearly strike his arm. Everyone expects a pen and a pen is the correct decision. Leaving the considerations aside for the moment, this is not "a deliberate act of a player making contact with the ball with the hand or arm." He has no reason to do this deliberately and give a penalty away. But he took an unnecessary risk and he is paying the price. In this case the "unnatural position" consideration is what determines the deliberateness of the act.
The OP is not as clear cut as my example and its a case of YHTBT. But from the description the considerations that I would use to make the decision is:
Does the player attempt to avoid the ball striking his hand/arm?
Is the hand/arm moving towards the ball or is the ball moving towards the hand/arm?
Since when did the laws consider risk?
This I'd expect from players.
It's all about deliberate handling of the ball, either you think it was or in this case think it was not.
I wasn't there, only the referee's opinion matters.


. Although the two documents are almost contradictory. There are many people who take up refereeing who will never look at things as in depth as some of us might on here i.e. what you have just produced. Very easy to read that throw away line in the actual lotg and not consider the position ever. I think the over riding feeling I get from the lotg statement is that just because the arm is in an unnatural position does not automatically mean it's handball which is what we hear about on the tele all the time. There needs to be a consideration of multiple factors and in some cases a combination of considerations before we can consider it an offence.