It really looks like you've got the billet brake bracket. From this pic it appears the casting for the caliper mount broke at the threads that hold the bracket in place. I wonder if the casting damaged due to over tightening the bolt that held the bracket on....that's what it looks like. I'd take it to the shop that put the extension on and suggest they over torqued that bolt and damaged the aluminum casting. Perhaps they will get you a better deal on a replacement piece.
Using a bracket instead of a brake bar isn't cutting corners, it's an alternative design.
Using a bracket instead of a brake bar isn't cutting corners, it's an alternative design.