It all boils down to communication. Sometimes you simply need to stay a little later than scheduled. It's unavoidable.
That said, if you're getting paid past your scheduled hours, I feel it's best that someone above you knows that you're staying, why you're staying, and what you are doing to minimize the extra payroll that you're using.
Example, this week POG team got hit really, really hard in my store (and I imagine every store). I ended up staying an extra 20 minutes or so to clean up. My ETL saw that the cart I was using was a mess. Lots of plastic wrap, old labels, cardboard scraps, reshop items, the works. Usually I'm a bit neater, but we both recognized that this week speed > cleanliness. If a messy cart and 20 more minutes is the price we have to pay to set 300 hours of POGs, but the POGS get finished, it's worth it.