Good evening echokilo......You certainly posted a very interesting question which will have been read by a lot of ABers; none of whom could offer an explaination for a calorific calamity. In fact I would doudt that an advanced mathematician would be able to reply; in the knowledge that U.K. water supplies do not contain any calories. (Perhaps it's contrary in the curry creative countries where river water might be used!! )
The only thought I now have is that you could, if possible, drop an e/mail to the manufacturer of the item concerned.
It's really got to me this one and my wife Viv is also unable to comprehend the calorie calculations. ( Keep a secret....I think she's better at maths than I am !! )
Carry-on cooking curries.....Best wishes....Ron.