Sir is right here. 

When one is just looking at flow of charges, the direction along movement of positive charge (or direction opposite to movement of negative charges) is taken to be the direction of the current (defined as such). 

In a simple circuit with a battery and a metal wire resistor, electrons will move from lower potential to higher potential. So, the current direction will be opposite. That's why it comes out that current direction is from positive potential to negative potential. 

So, in this case, sir is defining current by flow of charges and is not considering higher or lower potential.  

yes, thats exactly what m saying direction of positive charges is to be taken as current direction, so if u look the video properly u will notice that sir is considering flow of negative charges as current direction

Confirmed with Vaqqar sir. 

'Direction of current taken by me is correct but my sentence that negative charge is going up is wrong ,rather I should say that "positive charge is going from lower end to upper end" then only the negative charge at lower end will increase as well as positve charges at upper end will increase.'