I think you ran into the problem that there is some overlap in what DL serves for lunch and what they serve from dinner. I actually think this is reasonable from a logistics standpoint. There can't be too many cases where passengers are flying multiple meal-time 900+ mile domestic F flights on the same day unless it's something like OP's case (and I'm calling that domestic here for meal purposes) or connecting in MSP to go from the east coast to the west coast. I just don't expect them to look at the manifests, see if each pax's previous flight had a meal and what was served, and then cater accordingly.