Hi, I'm the author of the blog post and the paper. Every bug that was caught by the Haskel transition was verified to exist in the original Python. If I couldn't reproduce it in the Python, I fixed my translation. More information on my methodology can be found in the paper.
https://drive.google.com/file/d/0B5C1aVVb3qRONVhiNDBiNUw0am8...