The article means that Iran still doesn’t know what happened.  “Iran says ‘internal agents’ may be responsible for Natanz blast,” Maziar Motamedi, Al Jazeera, September 22, 2020.

“Zaghari-Ratcliffe files report of Revolutionary Guards harassment,” Patrick Wintour, The Guardian, September 22,  2020.

It looks like the U.S. will pressure Germany’s government and businesses to stop “doing business” with Iran.  “US accuses Merkel of failing to combat Iran’s terrorism and antisemitism,” Benjamin Weinthal, Jerusalem Post, September 22, 2020.