Comment by echion

> If you're doing a fake password hash to obscure timing, remember that it's fake and don't let the user log in!

I think this is the crux. Instead of doing the right thing, they tried to codegolf to get the desired behavior and it got real subtle, real fast.

this is a little flip: maintaining a security-critical program naturally pushes one to minimize code changes because a 30-line change is usually easier to review than a 100-line change. Except when it's not.