I had always heard an interesting story about that — since the newspaper was printed in Manchester, it was the first press runs that had to be sent to far-off London. Then the later runs (with misspellings often fixed) were sent to the closer cities.

On the other hand, newspapers based in London would send their typo-ridden newspapers to far-off locales first, and the corrected editions would stay in London.

Since the tastemakers were in London this resulted in a situation where the newspaper becomes notorious for being ridden with errors.

No idea if there's any truth to it, the wikip page presents a different story that sounds like problems with collaboration tools (eg. TTY) used between the two cities.