Even if this isn't based on similar questions that can be found online, a bug in existing systems usually wouldn't introduce itself by framing an isolated section of code. More often than not it'd be through indirection or a side effect that covers a larger execution path.

To an experienced C developer who works with the language constantly — probably. I'm not one, so I wouldn't know. I've found GPT to be much more helpful when you're working with technologies you'r not as familiar or up to date with.