The linked article does an OK job of documenting that contemporary news reports were too optimistic about how much Clinton's 1994 deal would constrain North Korea's bomb seeking. However, I don't think that's an adequate basis for "Clinton let North Korea get nuclear weapons" — not least because the article itself echoes, in apparent agreement, NBC's contemporary claim that NK already had a nuclear bomb.

Even setting aside that claim, I wouldn't be confident in inferring that "Clinton let North Korea get nuclear weapons" merely because Clinton made a deal and 12 years later (and 6 years after Clinton left office) NK set off a nuke. Given my original state of ignorance (I didn't know anything about this 1994 deal before this thread), I can't rule out the possibilities that (1) Clinton actually made smart moves which were later vitiated by Bush or a lower-ranked politician, or that (2) Clinton made the best of a bad hand, there being no reasonable counterfactual where a US president in 1994 could've ensured, without triggering some patently worse consequence, that NK's first nuclear explosion happened substantially after 2006.

(1/2)