My interpretation of the parent post is not that LLMs' output should be checked by humans, or that they are used in domains where physical verification is expensive; no, what they're suggesting is using a secondary non-stochastic AI system/verification solution to check the LLM's results and act as a source of truth.
An example that exists today would be the combination of ChatGPT and Wolfram [1], in which ChatGPT can provide the method and Wolfram can provide the execution. This approach can be used with other systems for other domains, and we've only just started scratching the surface.