That article is behind a pay wall, and it was purely an opinion piece. However, the author gave a longer version to be posted in a blog:
http://www.docbastard.net/2015/08/thoughts-on-brain-death.html
The short answer to your question is no. I don’t think the girl has recovered from brain death, not in the classical sense we think of when we talk about recovery from neurologic insult. But Fate has presented us with a more complex question, which could even be looked at as an opportunity to better understand this area.
However, I'm still highly skeptical because they haven't gotten anyone credible to examine the body. As it stands now, she's still legally dead. This retired doctor seems to be more interested in the classification of what death is rather than really forming an opinion on whether or not Jahi McMath is still alive. Even this doctor says that he would have recommended pulling her off the respirator.