I'm honestly baffled by this. You ate a small portion of food, that in total probably had 300 calories in it. You are more than two months out and this doesn't sound like it represents any kind of overeating. Just because you are eating healthier doesn't mean that you are limited to only eating healthy things for the rest of your life. The goal is moderation which it sounds like you are doing, don't try to convince yourself that you did anything wrong or that you "cheated." You ate what you wanted and did it in a way that conformed to your weight loss goals, so congrats.