To add to the ESD issue around 2:20 that's already been brought up :
In addition to what @tk321 said and @quakeguy81 's response, it being a safety hazard is not the only concern.
Sure enough it is definitely a hazard, especially if you have no idea why. Also yes, sticking metal objects into a socket can be done perfectly safely IF AND ONLY IF you know precisely what you're doing and understand the science behind electrical potential and electrical resistance—although at that point you should probably be smart enough to understand that even then it's a terrible idea and that you shouldn't do it. Even if you're "just" plugging it into ground and not something that's live, this means that YOU are the path to ground and that touching ANYTHING electrically charged has the chance of shocking you and possibly running lethal currents through your body.
But yes, ESD safety isn't, contrary to what some may believe as simple as "just grounding yourself" because ESD works both ways. If the components you're working with are charged in any way (which they very well can be—capacitors and batteries are very good at retaining charges, for example) then you could easily inflict reverse ESD because suddenly YOU are the path to ground and instead of you shocking the component, it shocks you (which can be just as harmful to the component!)
So what's the proper way? Simple, don't just ground yourself against an outlet or random metal object—but rather against the actual component itself! Grounding yourself against something other than the component itself only works if the component (and preferably the things around you as well) are ALSO grounded to the same point. Possibly the easiest way to achieve this is to simply put the components down on the side panel (avoid any windows, use the side without a window if possible!) and then attach the ESD stap to that same side panel.
