Exactly. Maybe the code needed to be rejected. Many developers have no problem pointing out issues in code. Anyone's code. You can see it daily on stackoverflow. Just because it happens to be a female from time to time makes it newsworthy.
It means it's worth looking into... which is what they're doing. They also discovered the code is more often from more junior developers, which leads to an investigation of whether or not women are having a harder time being promoted or are leaving the company more often.