The idea that Croatian commandoes would kill a US Cabinet official - when we had a US Army search & rescue team on the scene a few hours later - riding in a Chinook in over the mountains (still get chills even recalling the trip in that weather) - is too insane to warrant any further comment.
I don't have a dog in this fight -- I also thought Cahill's piece was over-fanciful, and posted some comments on the beacon issue. I'm skeptical, because it's a complicated way to kill somebody. However, I haven't researched it like he did, so I can't say he's totally wrong (and it is quite surprising how many Clinton buddies have died in airplane crashes).