Well, if this video illustrates the same thing... we have a BIG problem.
Now, If I honestly have to go by what is seen, the water and other scenery looks like it's curved in the video when he's using the binocular/telescope/zooming device (whatever it's called!) to view the tower.
It seems to me like one is looking up hill.
The next problem is that at the end of the video he admits it could just be refraction. There can't be a definitive answer/result when there is still an impedement, and that being the refraction.
http://hyperphysics.phy-astr.gsu.edu/hbase/geoopt/refr.html
As one who suffers not having 20/20 vision, I can tell you from first hand knowledge that the wearing of some glasses can make the ground immediately in front of you appear to protrude as though it were a hill, creating an illusion. So, while refraction is still a possibility - especially since he is utilising more then one lense - this material is not good enough for me, so I reject it as insufficient of accuracy and certainty.
Water seems like it is curved? It doesn't seem so to me, but this has nothing to do with the point of the video!
He never admits it could be refraction. Go back and read it like I did. He said "Can refraction really be the cause of this phenomena or does the earth just not look like a ball?" . He says this AFTER having shown that it could not have been refaction. So it is a rhetorical question.
It is unfortunate that he talks about the earth not "looking" like a ball, cause that has nothing to do with the experiment, but it's not important. He still makes the point sufficiently.
You cannot reject this based on refraction because we are talking about air refraction and not through water and glass like your link and reference talk about.
He also points out that there is not much moisture in the air and not much temperature difference in the air, which rules out refraction. The only downside is that he does not provide temperature and humidity measurements to show that. But this is irrelevant because you can SEE for yourself that this is the case.
Bear in mind that any kinks in the experiments are ironed out by repetition in different conditions. Something any good scientist will tell you is important. Here therefore is another one.
The more evidence you see of this, the less you will be able to reject this evidence.