It occurs to me that at least one thing you might want to do is to determine whether the programmer is 'friend' or 'foe'. All of the advice given so far will still have to take this small fact to account. If this were an ideal world, things might be different, but just the existence of such code suggests that there is a significant problem lurking in your organization. You might also do well to find out what backing this person has, I assume that he or she must have some, how else to explain this sort of mess? Actually the more I think about it, the more I think that this isn't a coding problem, this is an office politics problem. I suppose to be generous, the code and the person involved might be remedied, but such an investment might well cost more than it's worth.

Tactically speaking, I would assume the role of 'The Fool with Questions'. Essentially, have the programmer explain all of the anomalies you've found, to you, because you—of course, just don't understand. This way, the onus is one the author to either save themselves or not.

And if things truely get ugly, be prepared and bring copies of your node and the responses to it to the meeting! Just a thought!

–hsm