While I am a supporter of legalized recreational drug use and have nothing against people spending quality time with their lungs and a bong, I will be the first to say:
Pot and Serious UFO research do not mix. If you mention pot and UFOs in the same paragraph, its unlikely anything you say is gonna get taken
Did he indeed see secret U.S. government space fleet programs? Maybe. I wouldn't doubt it. But after he mention the joint, he aint gonna get taken
It could also be that say someone in the government added that claim of smoking pot in the story to make it less credible, or made him say it himself.
That way, if he mentions the space fleet, no one will take him seriously.
Its not totally impossible, you know. Could be the whole thing is disinformation.