Hi Robert,
All I know is this; "Kai San" or "Opening Mountain" is the entry form found in quite a few CKF styles.
"Hoi Sam" is the Cantonese pronounciation.
The form that I shot in KL, according to Sifu Yap, is "Shaolin Kai San" which is the beginner's form of Southern Shaolin.
The other Shaolin "San" form is "Hu San" or "Protecting Mountain", also taught in Shaolin lineages.
Got another clip here comprising of pictures extracted from a mainland WuZu manual.
http://www.youtube.com/watch?v=1RVD2LqUMEQ
Warmest Regards.
Eric