It wasn't code worth formally verifying, but even your description beats almost any programmer's first pass. With how good it is at finding bugs if you ask it, I have little reason to doubt its output.
In the real world, I'd say the 90% of the C code written is somewhere between "worthwhile to spend extra effort to detect and avoid memory errors" and "worth formally verifying".
Sure, for prototype sized codebases it might be able to handle finding mistakes a fresh grad might easily make, or even that memory bugs aren't a big problem - but in my experience it happily adds memory bugs to large codebases and multithreaded code (that I think an experienced human could easily spot tbh).
