Often people who wear their watch this way have a military background, which I don't think was the case here. He did start his career at a manufacturing plant, so perhaps it dates to that time where he wore it inside his wrist to protect the watch.
I don't think he normally wore his watch that way, the photos I've reviewed show a normal wear. I suspect he had the watch a bit loose that day and it rotated around while he waved his arms, as he was wont to do when talking. RIP, he was definitely a larger than life figure in the business world.
I didn’t work for GE, but I did work for folks who came out of the organization he created, and had a I had good working relationship with GE itself. Working to those high standards and expectations was an excellent foundation for a young procurement manager. God speed Jack.