Opinion wanted - Spoiled Lunch???

We are a married couple and had a disagreement over something that happened and would like your help and opinions. We will lay out the scene without alluding to who said what so as not to influence anything.

Almost every Sunday we go to lunch at the same place as a family. This Sunday morning we happened to be arguing over something so were both already in a mood towards each other. I started a shower to get ready to go to lunch. My spouse came into the bathroom and said that they needed to run two errands today and told me which two they were and then immediately left the house.

After I thought about the length of time it would take to go to the two places I guessed it would take over an hour at least. We wouldn't then have time to still do our usual lunch because the kids had a new music lesson in the early afternoon. Also, my spouse left the house close to the time we almost always go to lunch instead of waiting to do errands when we were out for the restaurant which would be more convenient because of where we live in relation to the town. 90% of the time we go to the lunch at the same time - my spouse prefers it that way. Given all this I made the assumption that my spouse had decided we weren't going out to lunch that day (my spouse is usually the one who decides whether we go or not) so after the shower I prepared the kids lunch and had them eat. My spouse returns after only 30 minutes running ONLY ONE of the errands and then is very disappointed I let the kids eat and that I had intentionally ruined family lunch because I was still mad over our previous argument.

The challenge is that my spouse only ran one errand versus the two. Had I know it was the one errand we still could have done lunch. The errand not done was further away so that gave more time.

I argue that since my spouse stated they had two errands to run and then immediately left that it was implied that was exactly what they had left to do. I simply can't see any other conclusion and made the best decision given what I had been told.

My spouse argues that stating to me in the bathroom that they had two errands to do and then immediately leaving does not at all imply that is what they left to do and that my spouse was just simply stating that they had two errands to run some time that day and that I was wrong to assume otherwise and didn't think it through.

We would love to hear opinions. Believe it or not this has turned into quite a disagreement.