I've been had!
Actually what occurred to me when seeing the photo was that the screen was tough as nails but I wondered if the way it was attached was a weak point (on holding the screen, not concerned about the ROPS). The bolts are essentially holding just one of the extrusions at the edge of the screen (wrong word but I don't know how to describe the metal part of the screen) and a full force hit from a tensioned cable has lots of force. I wondered not if the bolt was strong enough but rather whether the force would simply break the single bit of extrusion and allow the screen to bend inwards and let the object through. Not terribly likely I agree but then it occurred to me that using a greater number of screw clamps around the perimeter of the screen would distribute the force (say using eight clamps instead of the five bolts) and would capture the screen several extrusions inside the edge so if one broke the clamp would still have others to capture rather than lose control completely. My pseudo technical language here is imprecise so I'm not sure if the point is getting across. In any case the other advantage of using clamps would be that you wouldn't need to modify the ROPS just in case that became and issue with a dealer at trade in time.
