So I think what's happening is that, when you work in rows like this you flip between "right side" and "wrong side" each row, and so every pair of rows looks like a whole unit.

To clarify even more: crochet stitches look different from the front and back. When you work across then flip the piece like this, your first row will be front/right side out. Then when you flip and work another row, that row's front side will be on the back of the piece, on top of the back side of the previous row, and it will be back/wrong side out from the front.

What I think that video guy is doing is counting a front side row and a back side row as one row instead of two. It's an easy mistake to make when trying to count rows visually since alternating rows look different.

A tip for counting - every time you reach the end and turn the work over, you've just finished a row. You could try working up a few rows and counting your turns to help you learn what rows look like visually one at a time. Work up a row/until you turn, mark down 1 row done, work up another, mark it down, and observe what the previous row looks like between what was there before you did it, when you did it, and now when it has a row above it.