The only time a straight line is not going to be deformed by camera lense, is when the line is passing through the center of the lense (center of the image).

If you stop the video at the moment when the line of horizon is passing through the center of the lense, you will be able to see that it looks like a straight line.

The horizon is suppose to look like a straight line if observed from any height lower than 11-15 km .

The tower is far too low to be able to observe curved horizon. You need a high altitude for that.

All you are able to observe is a deformation of the straight line by the lense.

But, there are videos out there, taken from a plane, where you can clearly see that the line of horizon is passing through the center of the lense (center of the image), and is still curved.

If the image is not manufactured, it is a proof of curved horizon .

WS