Haven't read the entire thread so apologies if this has already been posted. Have you guys seen
this video, which zooms in on a piece of metal falling out of her pant leg as she walks? Someone in the youtube comments says that he thinks it is a catheter pin, then someone else links
here, the picture at which possibly corroborates that.
No matter what, it's just speculation, but it certainly is not a normal thing (at least in my experience) for a piece of metal to fall down through a pant leg, and it does require some sort of explanation.