I will not argue with you gmaxwell since you know the code much better than me.
My fear is about implicit consensus in the code that is prone to bugs. If this code is implemented differently on different clients there can be a fork where we would think there should be consensus.

I hope the libconsensus can help with this.

Peter Wuille explains it well, I think. http://youtu.be/asC_kVJ6sig?t=12m45s