Bad science reporting
whether livestock is more or less harmful than transport is not in the least bit relevant.
I'm not sure why it was ever mentioned, and I'm not sure why this comparison being inaccurate alters peoples opinions about the environmental impact of eating meat.
Surely the only relevant comparison is between the environmental impact of x calories of animal based food (meat) against the same calorie value of vegetable.
Any other numbers mentioned are just there because people want to confuse the issue.