I don't totally agree with some of the situations in the first video where there wasn't double line change. For example situation seen in 5:45 was pretty ok to me. He started braking after he changed his line so the car behind could have change his line to inside or backed off more imo but was too stubborn to do it. Sure you need to be careful in those situations as a car in front. But defending should be something else too than the obvious choose inside/outside in the middle of a straight, IMO.
-Matt

Thanks for the comments guys and I am glad these videos are useful. 

It is worth having the discussion, so we can try to agree what the right approach is.   In the particular situation you mentioned Matt, I agree that this one is a little grey area, but if you notice the Mclaren starts to drift back on to the racing line but leaves a little gap on the outside, then as they brake and the guy behind goes into that gap, the Mclaren drifts slightly further forcing him more off.  This is what I don't think is ok.  The Mclaren should have made his intention clear and gone all the way outside in the first place not keep drifting, but the guy behind should also have thought that gap is to small and backed off

Pretty much everyone agrees you can make one defensive move, or get in a defensive position, then only move back to the racing line if it is safe to do so, without causing the guy behind to have to take any avoiding action.  As one of the drivers said don't be a moving chicane, drifting around and making defensive moves to late, does not prompt safe, fast and close racing.