I tend to reject any narrative about the Soviets which makes them not sound like humans. They weren't all idiots or sociopaths: they understood, just like we do, that people make mistakes and that if you punish mistakes too harshly, people won't want to risk working with you. The Soviet government punished dissent harshly--but if you were working with them they weren't typically so foolish as to punish honest mistakes with a stay in the gulags. In fact, technical fields like their space program (and, for example, infrastructure programs) were safe havens for intelligentsia, where some criticism of government was tolerated because it was understood that criticism from people with technical knowhow was necessary to progress Soviet goals.
There are exceptions I've found, but I tend to think those are the result of a few people with too much power making bad decisions, rather than a pervasive cultural norm.
None of this should be perceived as a defense of Soviet totalitarianism. Stalin has the highest body count of any dictator by a wide margin, and that's totally reprehensible. All I'm saying is I think he killed political dissenters, mostly, not allies who made mistakes.