[lvevjo]

The article is pretty old. Has anyone tried to exploit this loophole since then?

[Sniffnoy]

Actually, yes. Here's a recent article overviewing the subject: http://www.vox.com/2014/5/22/5738756/you-can-kill-someone-in...

Scroll down to "an actual case". Mind you, AFAICT, they didn't travel to the 'zone of death' intentionally to commit a crime; but, having committed a crime there, they did attempt to use this defense.