Just one problem with your theory. The Monero devs, Anonymint and even rpietila have acknowledged bcx exploit is real and they are working on fixing it. My theory is bcx proved it to them and then did not pass on the fix.
We absolutely have NOT said that. We know virtually NONE of the details of the claimed exploit.
So far all that third-parties have produced is a rehash of the research done and released as part of MRL-0001, which can be found here:
http://lab.monero.cc/pubs/MRL-0001.pdf