When Wong Yung fooled Yeung Gor into believing that Little Dragon Girl had disappeared with the Southern Seas Divine Nun, she fabricated the story that her own father, East Heretic Wong Yerk See, had once met and learned martial arts from the nun. For the next sixteen years, Wong Yung worried that Yeung Gor would encounter Wong Yerk See and discover the truth.
That was an uncharacteristic mind fart for Wong Yung: if she wanted to maintain plausible deniability, she shouldn't have used her father Wong Yerk See. She should have used her dead teacher North Beggar Hung 7 Gung. Dead men tell no tales. With Hung 7 Gung long dead, Yeung Gor would never be able to verify the story.