The preceding sentence was changed to be more explicit that the bullet points are about the "user-facing API" being unrealistic. They're not implementation rules/constraints.

I think his solution is a little bit tongue in cheek - it shows how much easier it is to solve using transactional memory compared to low-level concurrency primitives. So it cheats by using very powerful techniques instead of the very weak ones that the post says to use. You couldn't use his solution in C++ for instance, because C++ doesn't come with garbage collection or transactional memory.