The CIA document, as the video points out, is weak if used alone. However, there does exist good evidence of the soviet system of democracy. Defense of Stalin against Red Scare mythology is complex, and ultimately Stalin was neither a saint nor a monster, but a socialist head of state under extremely turbulent conditions.

I myself have used the CIA report, not because it absolves Stalin of any excess (which is to fictionalize Stalin into a saintly figure), but because of the line describing his leadership style as more of a "captain of a team," which is backed up by reporters like Anna Louise Strong's first hand experience.

Finally, it's important for any ML to recognize that no socialist project has been free of sin, no socialist leader without bloodless hands, including innocent blood. People often get caught up in historical debates more than they do material reality of today. We must know our history to know how best to learn from our mistakes, but too often Marxists debate which historical figure was morally superior, vs which was theoretically and practically correct.

Stalin was more correct than Trotsky regarding the issues they debated at the time, such as socialism in one country vs permanent revolution. Stalin had a better theoretical line regarding the peasantry, and ultimately did oversee the world's first Marxist state and navigated tumultuous waters. Trotsky did more than a fair amount to undermine socialism, and Trotskyist organizations have been more of an enemy to socialism than an ally, with few exceptions. Trotksy was sometimes correct, though, such as analyzing fascism. Neither were perfect saints nor devils, even if Stalin was better than Trotsky.

All in all, what's important is connecting theory with practice, learning as we go. If the strength of our ideology rests more on the morality of those that contributed to the creation and refinement of Marxism-Leninism than to the actual practical use of said ideology, then Marx would roll in his grave.