[Scott Mahrle]

This does not add up:

the worm subsequently grew at an astonishing four centimetres a week... Twelve weeks later... Mike passed out an intact, six foot long tapeworm.

At four centimeters per week, after 12 weeks the worm would be 48 centimeters. That's only about 19 inches, not six feet.

[alnitak]

The advanced math was obviously too much for the BBC editorial dept. Most journalists are still at the "some beans" stage of arithmetic. They even mixed up the units, moving from cm to feet with the sort of wanton abandon which would do NASA proud.

If we assume 4 cm PER DAY, we get 4x7x12 = 356cm, which is a lot closer to 12 feet.