What he showed is it is all in how you handle them. He also mentioned that when someone mishandles a hive that the next time they get near the hive they get attacked before they opened it. Treat your bees as you want your bees to treat you.
I have noticed that, sometimes i can be a bit clumsy and bump a frame or 2 i once dropped one with bees on it, and yes they did go me the next day just walking near the hive. Ive found if they start to fire up ... if i back off for a bit then they calm down again, seems a couple set more off..