Whose Arm Is This?

This broken arm appeared on my roof three months ago and has not moved. (I placed the penny there today for scale.) Accessible only by me and satellite dish installers, the roof is three very high stories up. Balls don’t end up there. Nothing ends up there because it isn’t a place you’re supposed to hang out: no guardrail, no deck or anything, just shingles to sneak onto from a private and weird staircase that juts out of the kitchen. So, the first question is: how did it get up there? And the second question is: who did it come off of? It has sharp edges along the break, makes a tinkling sound like china when you drop it, and is holding a rag or washcloth in it’s hand. Theory #1: it was born that way and just The Gods Must Be Crazy-ed itself out of the sky.