Makes perfect sense ! The UPS man normally makes deliveries around my area around 11am to 1 pm from past experiences, I saw him make a delivery to my neighbour and thought im next but he drove off so like you say my parcel wasn't even on his van in the first place!There internal performance measures. They didn’t really put it out for delivery but by saying they did means that depot met its performance targets. Of course they then have to deal with the fact that they didn’t deliver it - simple, regardless of what they tell you, internally they will mark as the customer‘s fault.
So there you have it, in reality a poor service but on paper a perfect one. Praise heaped on the depot and the manager for delivering such a flawless service.