The way OpenAI used GPT-4 is fundamentally different than how GPT-4 was used to score the answers to the MIT exam. In OpenAI's case, they had GPT-4 generate an explanation of when a neuron in GPT-3 would fire. They then gave that explanation back to GPT-4 and had GPT-4 predict when the specific neuron in GPT-3 would fire. The scoring was done by computing the correlation between when GPT-4 predicted the neuron would fire and when it actually fired. The scoring was not done by GPT-4 as was done for the MIT exam
In addition OpenAI did have human evaluators score the explanations as well to make sure they were human interpretable[0]
[0] https://openaipublic.blob.core.windows.net/neuron-explainer/...