For a piece of software designed by reading the specs and implementing accordingly, there acid3 would be a good way of demonstrating the quality of the result.

But is that what happened? If you pass tests that conflict with the specs, then that implies that the implementation is not based on specs, but on feedback from the test. Which means it may be designed to pass the test, and not much good once you go outside the test examples.

I'll extend the benefit of the doubt and say that it's possible that the implementation is based on an older version of specs, one that matches the tests. But it doesn't inspire confidence that all we're shown is a single screenshot and no source code.