Have you ever flown a plane with no engines turning? Pretty quiet. Half the time when I'm running, my eyes are squinted/shut from sheer hatred. If you can't hear it and can't see it, (especially coming from behind you while listening to music...) you're not gonna know it's coming.
I run the same way, Otto. However, when I run outside I don't like listening to music because I like to know what's going on around me, especially if I am running on a busy road or somewhere else with a lot of traffic.
I guess what I am getting at, is no matter where you are, you have a responsibility to be aware of your surroundings for your own safety and the safety of others. I don't know about you, but with all the idiots on the road that seem to ignore bikers, runners, and joggers I have to stay aware of what's around me to stay alive.
All in all, it's a tragic accident that may or may not have been avoidable.
Ohh and on another note, I have been through the same training program as you (granted I went the P-3 route) and have a decent amount of civilian time. I know a plane with no running engine is pretty quite.