Factual error: Hydrofluoric acid is so dangerous that no high school chemistry lab in the US would have a thimble full of the stuff around, let alone gallons. While it's incredibly toxic it's also a very poor choice for getting rid of bodies, which Walt would know.
Suggested correction: Walt also has never had to dump a body before. Hydrochloric acid would dissolve enough of the body to make it unrecognizable and easier to move, especially in a proper container where it can be transported. Plus this acid was more readily available to Walt and Jesse at this point in the series.
This isn't a valid correction. First, hydrofluoric acid was used, not hydrochloric acid. Second, just because Walt never had to dissolve a body doesn't mean he thinks it would. He should know as a chemist that it wouldn't. Third, you missed the point that no high school would have hydrofluoric acid on hand. So how can that be more readily available than something common and effective like lye.