Seems the most plausible to me, too, tbh.
Some type of surveillance device, drone maybe, was discovered and taken out. Grassley, here, telling the bad guys he broke their shit.
Grassley probably a bird hunter, as an Iowan farm boy, so he's got the perfect shotgun for the job at hand.
Not sure about senator, but haven't cabinet members already been confirmed?
Quick look through cabinet shows 4 women, DeVos and Chao (McConnell wife), Haspell and Carranza. Don't see anything possible there, but not sure.
There is Ratcliffe and Scalia, though.
Holy shit, imagine the son of Antonin Scalia being appointed. Stick a finger in their eye and turn it a few times territory right there.