It's not. There was no correlation at hand here - this was just a coincidence
This is a fairly typical informal usage of the word correlation in my experience, and while it might not be _technically correct_ (I don't know, I'm not an expert), it's an often enough used idiom.
The bug simply was not "a good example of correlation does not equal causation" as any statistician would use the phrase. That's my only point. OP is free to type whatever words he wants into the comment box and press send