to say that cake lining video tip is rubbish?

[shirleybasseyslovechild]

that tin is not really lined, is it?

No. What you need to do, but they didn't show is to draw around the base of the cake tin, cut out a bigger circle, and cut snips from the edge of the big circle to the circle you've drawn. That takes the same length of time, but does actually line the tin. Or just buy reusable pre-cut liners.