Since the introduction of electronic calculation of the take of data, the ability to work out the 'best' configuration changed dramatically. On the 747, we basically used just the one setting, because it was too time consuming to calculate the data for multiple settings. Laptops and iPads changed that, so that now you can see an entire range of settings being used, and it's common to see takeoffs with very little flap. If you don't have the correct setting, the aircraft will not rotate and lift off normally, and the video seems to show a normal rotation.As far as I'm concerned, I can see no reason to continue with the flap theories.