I'm with you 100% on this. I have never owned or used ARC rings, don't care for the design, just my personal preference. But even if I did, no way in hell I would be torquing the single bolt to 50+ inch pounds. In a previous post someone posted one of his emails where he likens tightening his single bolt to 55 inch pounds being equivalent to 25 inch pounds on a two bolt, traditional ring. If that's true, 25 inch pounds is WAY too much torque on a traditional ring setup. 15 inch pounds has worked perfectly for me on dozens of guns. Nearly every scope manufacturer on earth recommends 12-18 inch pounds MAX. Not sure what the equivalent would be on ARC single screw rings, but I bet it's a lot less than 55 inch pounds.
I'm still going with the OP over tightened the rings and damaged the lens.