Can We Trust the AI Pair Programmer? Copilot for API Misuse Detection and Correction

API misuse introduces security vulnerabilities, system failures, and increases maintenance costs, all of which remain critical challenges in software development. Existing detection approaches rely on static analysis or machine learning-based tools that operate post-development, which delays defect resolution. Delayed defect resolution can significantly increase the cost and complexity of maintenance and negatively impact software reliability and user trust. AI-powered code assistants, such as GitHub Copilot, offer the potential for real-time API misuse detection within development environments. This study evaluates GitHub Copilot's effectiveness in identifying and correcting API misuse using MUBench, which provides a curated benchmark of misuse cases. We construct 740 misuse examples, manually and via AI-assisted variants, using correct usage patterns and misuse specifications. These examples and 147 correct usage cases are analyzed using Copilot integrated in Visual Studio Code. Copilot achieved a detection accuracy of 86.2%, precision of 91.2%, and recall of 92.4%. It performed strongly on common misuse types (e.g., missing-call, null-check) but struggled with compound or context-sensitive cases. Notably, Copilot successfully fixed over 95% of the misuses it identified. These findings highlight both the strengths and limitations of AI-driven coding assistants, positioning Copilot as a promising tool for real-time pair programming and detecting and fixing API misuses during software development.