I shudder to think that using flaps to control glidepath is really a normal thing
Certainly one can prove you can fly around the pattern with elevator trim and opening and closing the doors of the plane to make turns
BUT YOU DON'T DO THAT normally.
And what would the pilot in question do if he were flying a plane that didn't have flaps! OH NO, he couldn't possibly fly a plane that didn't have flaps.
And what if he had an electrical failure and couldn't change the flaps?
IF you want to experiment, you can do it without passengers on board.
It isn't cute, it isn't right, it isn't good flying.
And using the BA 777 at heathrow as an example is pretty lame. And didn't the captain lose his job? Hmmmm.