Exactly one month ago, Iranian and Lebanese users on social media were gripped by the dramatic killing of a couple driving on a highway just north of Beirut. The suspected Israeli targeted assassination raised eyebrows as it was the first recorded in a predominantly Maronite Christian area where Hezbollah's influence is limited. The incident in Jounieh gained further prominence after Iran’s embassy asserted that an Iranian woman, Masoumeh 'Arezou' Karbaschi, had been slain along with her Lebanese husband, Rida Awadah, a reported member of Hezbollah.

The killing additionally grabbed attention—and sparked heated speculations—because of how it unfolded. Taking place in broad...