I believe that he had his stroke after they finished filming.
Anyone seen The Grandmaster (http://www.imdb.com/title/tt1462900/)? It's another movie about Ip Man. I thought it was Ip Man 3, but apparently Ip Man: The Final Fight (http://www.imdb.com/title/tt2495118/) is the 3rd movie. Unfortunately, Donnie Yen isn't in either movie.
Havent seen The Grandmaster, BUT, I have the FOURTH installment of the Ip Man saga, The Final Fight on order, well see how that goes
[video=youtube;NkHyYQyARAE]http://www.youtube.com/watch?v=NkHyYQyARAE[/video]