I am not sure but I guess Pak mei was himself not necessarily a Hakka. Nor was his art passed down to his disciple monk (and his monk disciple) on the basis of their ethnicity. For example, I doubt that the monk Chuk Fat wan was a Hakka. Even if he was, a Buddhist monk is supposed to have abandoned all forms of identity after taking Buddhist precepts.

The reason why I am interested in non-Hakka version(s) of Pak Mei is because the Hakka arts are usually very compact and "restricted". In other words, there is not much emphasis on mobility, speed, agility and expansion of the body with freedom. I believe if there was a non-Hakka Pak Mei still extant then it must show quite different characteristics. My guess is that a non-Hakka variant of Pak Mei would rather look almost like a Northern style (like Choy Li Fut, Wu Zu Quan etc).

There was a very good video around in youtube posted by "SifuWu" which shows a boy demonstrating a set called "Stone-Lion" set and this looks quite a lot like Northern styles with characteristic low stance, expansive steps and significant speed.