Well the statement was that it was not possible to remove the overhead of method_missing (well they didn't actually say 'impossible' but that's how I read it, and I also took them to be referring to peak performance, because people usually are).

I solved the problem of showing that it is possible to do that. Before people thought it was impossible, and now they know it isn't.

I'm not claiming I solved other problems such as removing the overhead with low memory or removing it in corner cases.