He was into the wind...Look at the flags on the video......
And beside that, nobody does a Cat A take-off tailwind, it is head wind, crosswind with a head wind component....
You can climb to 400ft like that.....the confined area is 100ft to 400 ft TDP....
And it is a stadium, do you need something bigger when you have a huge flat surface with all reference you need to land?????
All those PPruners who can already determine everything.....
Painful !