You can bend a note in either direction. Tighter embouchure is sharper, looser is flatter. Have a go.
Bending up is possible, but not very much and only if you have a cvertain relaxed embouchure to begin with.
It's much easier to bend down, and possible to bend a lot further. I haven't watched that DVD (I know), but from what I remember I demonstrate bending down then up.
To bend up significantly, you have to start with the note already bent down. This is tricky unless you've first of all practised a lot of bending down then up. You will gradually get the hang of how to start a note with the relaxed embouchure so it's under pitch (flat) and bend it back up to pitch.
This is the opposite to what a guitarist does, you can't bend a string and make it go down, when you push the string it gets tighter and so the pitch raises.
To make a downward bend on a guitar, you start with the string already pushed sideways to tighten it, then relax back down to pitch. (Or you can loosen it with the machine head)