i'm not going to start giving nutrional advice to a doctor, so i'll try and skip that part. although i will type, what to me, seems obvious: a proper breakfast or lunch should be more than enough for a 38 mile race. eat a powerbar/etc 20 mins before the start if you're really concerned, and bring a gel or something as an emergency plan.
if you do a couple of 2+ hour training rides every week, then you should have been fine for the distance.
i'm guessing it was just a jour sans.