There is an error at 3:45 where it is erroneously said that the left group goes down and the right group goes up. The correct orientation is that the groups on the left go up and the groups on the right go down.
The orientation for the L and D sugar CH2OH group mentioned earlier is still correct.
L-sugars = CH2OH down
D-sugars = CH2OH up
Groups on the left = up
Groups on the right = down
The below file shows the correct diagrams with changes marked in red highlighter.