I was planning on disagreeing with him on this, but other than this he's the coder around here I most trust, so I wanted some backup before I pick a fight.

They have a wonderful saying in Texas that goes something like this: "Be sure your words are soft and sweet, just in case you are forced to eat them" ;)

I find that what works better than 'picking a fight' is a somewhat surprised disbelief that the situation is as the code reviewer describes. Think about it -- what advantage is there to using DBI if it sometimes messes with the ordering of the data? That doesn't sound like a feature to me, it sounds more like a bug.