Would it be too much to identify the title of the NPR article? Or perhaps even provide a link to it?
Is the article an editorial (and if so, is it op-ed or NPR's own) or news reporting and/or analysis? A link or something that'd allow us to know of what article you/Fox remark would help answer that question. The nature of the article matters because it tells us who bears the preponderant onus for the mistake and credit for having the integrity to issue the subsequently provided correction.
As for the matter of the correction:
- According to the video NPR issued a correction five hours -- not fifteen, fifty, five days or five weeks, months or years later, but five hours -- after publishing the article.
- That's definitely a timely-enough correction that there's no basis for recriminating NPR for having made the mistake. The error came quickly to NPR's attention and it corrected its article to reflect the verity of the matter.
- Five hours later hardly sounds like NPR's being "forced" to issue an apology. It sounds like NPR learned of (realized) its errant assertion and amended the article to correct it. That's what one expects of anyone who publicly makes an untrue/inaccurate assertion about something verisimilitudinous.
- Did NPR issue an apology? Trump, Jr.'s tweet and the text of the video indicate it did not.
The lady doth protest too much, methinks.
-- William Shakespeare, Hamlet