They presumably first read an article on another site such as CNN that mentions electronic jamming: https://www.cnn.com/2019/07/18/politics/trump-us-destroyed-i... but then decided to share an article based on it from a particular well known source such as WSJ in this case, that happens not to mention what they included in the title. So yes, the person should have shared the actual article they read and that they based on the title on.

Submitted title was 'U.S. Destroys Iranian drone using “electronic jamming”'. We changed it to the article title as the site guidelines ask.

https://news.ycombinator.com/newsguidelines.html

The linked article doesn't mention it.

CNN reports[1]: The drone was destroyed using electronic jamming, according to a US defense official

1 - https://www.cnn.com/2019/07/18/politics/trump-us-destroyed-i...

It is mentioned in this article.

https://www.cnn.com/2019/07/18/politics/trump-us-destroyed-i...