OR, maybe the universe is just trying to make it look like a coincidence! Bloody cosmic conspiracys (they’re the things that keep me from spelling, too)
No, but then I don’t think that “prison of your own device” is as unique a phrase as “twilight’s last gleaming.” I’m not saying the phrasing was a coincidence – how would I know? – just that I don’t think we can say for sure that it was not.