I agree with

do not leave a paper trail, face-to-face is better.

also prepare to bring a solution to problem on hand, such as comprehensive unit test and code coverage, otherwise he/she will think you are just a whiner.

curious how your organization manages bug fixes, do you use any change management tool? I usually assign bugs back to the culprits themselves, unless it's just some really simple ones like a typo, then I'll take it and of course the credit too.:)

good luck!