I can write tests. I just prefer not to, for the sake of productivity and preserving sanity. If you disagree that I can write mostly bugless code, I challenge you to find some bugs in my open-source projects :)
If I don't use it because it doesn't pass my peer review process, whatever that might be, then my competitor will use it and come up with a faster/cheaper solution than my one.
Peer review is not for filtering software. Peer review is process which used by (professional) developers to help each other to catch bugs and share experience and best practices.
Basically, I said him that I found bugs and/or bad practices in his code.