Like clutching a rope tied around your neck?
It could have looked like clutching a rope. I think it was more a case of NOT holding their hand over their heart, or standing at attention. They had to put their hands somewhere, so tucking them into their collars was about the only option. There were a number of them doing it. I guess I’d have to look for some older clips, say 2 years ago, and see if that was a practice back then.