OK, I looked, and he did not say it was impossible. It is not impossible that I have a flying, fire-breathing dragon in my garage either, just rather unlikely.
I would like to point out the 'bait-and-switch' inherent in your argument. You claim that it is "not impossible" for various countries to be communicating with aliens, then segue into a list of global superpowers which you claim are "in contact", and that they have "secret programs", and that if we think the "government is not hiding anything" that it doesn't mean it's not happening.
This major fallacy in this argument is question-begging. You are the party making the positive claim, that 'world governments are in contact with aliens'. It is therefore your burden to show that your proposition is correct. As of this point you have not done so.
Instead you use this 'bait-and-switch' type of argument: that world governments, specifically the US, China and Russia "have some sorts of secrets programs", and that they are "hiding" this contact. Arranged in the standard form of informal logic, your argument goes like this:
p) If world governments were in contact with aliens they would conceal that contact.
p) China, Russia and the USA have officially secret programs.
c) Therefore China, Russia and the USA are in contact with aliens.
The fallacy here hinges on the existence of secret programs, which is a no-brainer. Every government, large or small, that I can think of has some secrets. Having a secret program does not validate your first premise, because there could be many 'secret' programs. Let us say that the U.S. government is developing a new weapon… let us imagine that they are developing a way to 'guide' a sniper bullet by laser. Not just aim it, but have the bullet course-correct like a guided missile. Such a development would be a major advantage on a battlefield. A well placed bullet can disable an aircraft or even take out a radio antenna on an armored vehicle. Such a program would be an official 'secret'. Here is a rather mundane example of a secret program that does not involve aliens.
Regardless of the existence of secret programs, your first premise is not shown to be true.
I would also like to point out the "no true scotsman" argument in the next phrase: "similarly to 911…people still believe that story about terrorists and stuff. Average intelligent human can't fall for that."
You dismiss the official 9/11 story, that terrorists crashed airplanes into the World Trade Center towers, and state that "Average intelligent human can't fall for that", which immediately throws into question the intelligence of anyone who disagrees with you.
The No True Scotsman fallacy takes the following form:
Argument: "No Scotsman eats pudding."
Rebuttal: "I am a Scotsman and I eat pudding."
Counter-Argument: "No true Scotsman eats pudding."
… which throws into question the status of the respondent as a "true scotsman".
Frankly, I've seen "Project Camelot", and I am underwhelmed. Let me just say that I am not surprised that you find their arguments convincing, considering how poor your skills at argument and informal logic actually are.