Did you watch the video? Did you not see the logic (and conversely, the incredible volume of illogic in the "chem"trail claims??)
Since this thread's topic is a YT video that shows clear logic that blows the "chem"trail nonsense out of the sky (see what I did there?), here's another that uses more logic, plus some geometry and math. What's particularly compelling is that it was videoed and posted by a pilot.
( It has two "parts", the first section is relevant, the last part is about another particularly silly claim by so-called "chemtrail knowers" ):