Do you know what tactic Grandmaster Wong uses to trick Sifu Mark Blohm?

As the course participants improve their skills in chi sau, they soon discover that it is easy to deflect opponents’ attacks. Reversely, it is not easy for them to strike their sparring partners. This leads to the next stage of combat efficiency, that is, finding new ways and means to defeat opponents when the current stage has become inadequate. An excellent progression is to move from techniques to tactics.

Grandmaster Wong demonstrates two effective tactics on Sifu Mark Bholm. He explains that Mark knows the techniques and has the skills to deflect his attacks, yet by employing some tactics he can still strike Mark despite his knowledge and skills. Do you know what tactics Grandmaster Wong uses?