Same thing happened on my Rome Mob bindings. Rome sent me out a replacement. This sort of design for "tool-less" forward lean adjustment is found on a variety of bindings, including Rome and Union. I am not a fan of it at all. It's a weak point in the set-up and according to Rome can come loose very easily when riding. I would rather have a set up where I'm securely adjusting forward lean with the usual #2 or #3 philips screws to hold it in place, rather than this type of tool-less mechanism that you twist and adjust to hold.
Burton and Flux seem to have better tool-less forward lean adjustment on their bindings. My Malavitas are easy to adjust and have no twist mechanism design that will inevitably come loose and separate.
Yeah, I was kind of surprised by how poorly designed that element was. It seemed like the screw was only one or two turns away from falling out. I think it popped off because the back of my binding was rubbing up against the foot rest on the lift. It wasn't too big of a deal though, I just moved the one in the back to the front binding where I need the lean a little more. I shot them an email. Hopefully they get back to me soon.