There is no particular magic in the lemonade itself. The main working factor is the "fasting" aspect and giving your digestive system a rest and then the ingredients in the lemon helps the empty system in alkalinizing and providing vitamins, the cayenne helps in stimulating circulation and loosening mucous and I believe it is also high in vit C and B and the maple syrup provides carbs and minerals to give you energy to help you function since you're not taking in calories from solid food. I doubt it very much that whatever you went through was related to drinking the lemonade unless your system was reacting to all the extra sugar from the maple syrup.
There is no such thing as a "partial" MC. Specifically when you are eating ANY solid food. Your digestive system remained fully active and the main working mode of the MC or ANY from of fasting is giving the digestive system a rest.
All you did was add a good amount of sugar calories and getting some of the vitamins and nutrition from the lemonade ingredient. Because you were eating solid foods and your system never entered fasting/cleansing mode it's highly unlikely that you got enough detox from the cayenne while eating regular solids to have caused any maladies.