The mechanisms that make this not strictly true (and there are many) aren't really worth your time and focus when thinking about diet and exercise, unless you're trying to fool yourself into not doing something difficult.
Nope. A calorie is a thousand calories. It's a silly, ambiguous measure. Kilojoules is unambiguous and should be used instead.
The post I was replying to wasn't about confusion in units. If it helps you, read it as kCalories, but the distinction is not important here.
The mechanisms that make this not strictly true (and there are many) aren't really worth your time and focus when thinking about diet and exercise, unless you're trying to fool yourself into not doing something difficult.