I've been doing a lot of pre-pro lagers recently and was wondering what your malt bill and mash schedule was like, if you wouldn't mind posting it.
When in doubt about the presence of diacetyl, you could always test it, check out this link if you don't already know how to do that.
www.winning-homebrew.com/diacetyl-test.html
Finally, I don't think a short rest in the high fifties, or low sixties ever hurts, and it can even help reach final attenuation if you haven't already.