I think everyone does this occasionally, especially if you write a lot of short fic and/or have a bad memory. For example, I re-used the same Terminator / Angel / Highlander name gag in two stories
here ; my excuse is I wrote them three years apart and didn't notice until I was looking out stuff to post to a Highlander site. In other stories I have multiple instances of sunlamps used against vampires, etc. etc.
I don't think I use the same turn of phrase in multiple stories quite so much, but there are undoubtedly things I do recycle. So long as it's my own work I'm borrowing I don't worry too much.
