I'm saying that the article doesn't mention Signal the application a single time in any of the forensic work detailed.

The WhatsApp exploit is zero click and is installed on the victims phone via an infected PDF being sent to the victim by an unknown number.

That level of detail on the WhatsApp exploit, plus 0 mention of Signal the application in the article, Plus unknown contacts cannot send you a PDF in Signal unless you approve them first.

Signal is a much bigger accomplishment to hack than WhatsApp. That makes it more interesting to detail how it was hacked if you have any evidence that it was.

Seems to me that an overzealous editor messed with that headline before publishing.