[i_cannot_hack]

They mention false positives as well on github: The rate of false positives is harder to measure, but based on limited manual reviews it's well within 20% range and the majority of it is a gray zone.

[kleiba]

Hard to measure, how? Either something is a bug or not - otherwise how would you be able to count anything at all?

[lstodd]

Assign each line of code a bugginess factor then count those exceeding an arbitrary threshold obviously.