It doesn't really work like that. On the Tour de France a cyclist will consuiem around 6,000 calories per day, but will use them up.
It depends on his metabolic rate and his activity levels. Starving yourself will slow this down, and overloading will speed it up. Metabolism is the way your body uses up calories from the food you eat and turns them into energy. Metabolic rate is the speed at which you use up those calories.
Dropping your calorie intake below 1,000 calories a day on a CONSISTENT basis will signal your body that you are in starvation mode, and will slow down your metabolism. Ditto, visa versa. When the metabolism slows, we store food as fat and gain weight. Calories do count, but it's also about how efficiently your body burns those calories.
For a broad outline, multiply body weight in pounds (lb) by 11 to establish the amount of calories you would need to consume per day to lose weight. If you're very active, you can multiply your weight by 12. (e..g. 10 stone person needs 1,540 per day)
Calories aren't bad for you. Your body needs calories for energy. But eating too many calories - and not burning enough of them off through activity - can lead to weight gain.
If this person was doing this consistently, then it would have an adverse effect over time. However, as it would be a one off, the same calories would probably be burnt but over a period of time. Hence, a calorie is a calorie, whenever you take it.