The Soviet communist leadership was genuinely scared of Gagarin, as he was undoubtedly the most popular man in Russia sinch GeneralZhukov, a simple man of peasant stock who was remarkably brave and a genuine world hero. Russian friends of mine are convinced that the KGB sabotaged his plane on orders from above.
Your friends aren't alone. Gagarin was a threat to the commies, and it sure was convenient that he died a hero's death when he did.
I'm Russian and have never met any other Russian who thought differently.