Not dumb actually.It's to tie up loose ends, but like I've said it before, it's an incredibly dumb move strategically. But it's done to show us how dangerous the people we are going against are and show the threat for the MC and Polygene overall.
While it would be pretty fucking obvious that she was most likely killed because of what she gave to the media. The investigation into her murder will go nowhere. The evidence for that is on another country and most of what they need to advance the murder investigation is out of their reach and would be illegal for the country of origin to give it to them.
Any substantial evidence like DNA linking the bald dude is unreachable to them and illegal to give it to them.
It is very obvious and, in their face, but they can't do anything about it.