It's still a science goof. A technobabble explanation by another writer YEARS AND YEARS after the fact doesn't change that the first writer didn't know what a parsec was.
Yeah, but it's pretty clear that Lucas did
know what a parsec was way back in 1977. The only reason that it's an issue is that fans have trouble wrapping their heads around the fact that Lucas had his character utter some bullshit. To make sure it was bullshit, Lucas had to misuse the term, and the only way to misuse the term on purpose is to know how to use it correctly. If the scene failed, it failed to anticipate that people wouldn't get that Han was bullshitting when he said it, leading to years and years of overblown controversy, over-analysis, and wanky explanations, like going around a black hole at the shortest distance.
Or, what Christopher