OpenAI revealed that several of its AI models, including GPT-5.4 Thinking, underwent accidental chain-of-thought grading during reinforcement learning training. Despite this, internal analyses showed no significant degradation in the models' ability to demonstrate their reasoning processes. The incidents affected less than 3.8% of training samples, with some training runs inadvertently rewarding or penalizing models based on their internal reasoning steps. External organizations such as METR, Apollo Research, and Redwood Research contributed insights, confirming that the minor incidents did not harm monitorability. OpenAI has since enhanced its detection measures to prevent future grading errors, implementing automated systems to catch chain-of-thought grading contamination. The announcement had no immediate impact on AI-related crypto assets, as the integrity of AI models remains crucial for blockchain applications reliant on transparent reasoning.