Leaving the insulin out overnight shouldn't be an issue, really. It's not ideal, but generally not a problem. The pens were really designed to be out, so people could carry them with them. Refrigerating does extend the life, but don't worry about one night.
It MAY be getting a little old since the pen was started in January, but many people do get quite a bit of time out of their pens and vials.
Did you happen to retest at +6.5? I wonder if that was a bad test or bad strip.
It's possible this could be a bounce. Any chance Milo has gotten into any contraband?