OP - I appreciate your experience report. While the park hopping rules are clear, they do take a little getting used to in practice, especially for APs and frequent guests who may be used to moving around property at will.
I could see something like that easily happening to us. We often have days where we adjust the plan on the fly - some stay at the pool for an unplanned resort day, some hit the park as intended, or whatever the case may be. It’s a lot easier to sit here from afar and think through any unintended consequences of park dining plans that evening than it is in the throes of a WDW vacation - so it seems to me a very easy mistake to make.
Your post will help me keep things like this in mind on our future trips.