Why do DPD lie about attempting delivery rather than just cancelling if they can't make it?

I literally watched a DPD driver lie to me in real time today, I was tracking as he came up the street. When he was around ten stops away, I get a notification saying my parcel couldn't be delivered because I didn't provide a PIN. My ground floor window overlooks the front door, this man was 100% never anywhere near my door. When I called the business to get in touch with DPD, the fact the van had been on my (very long and interconnected) street at some point during the delivery window was apparently proof enough that delivery was attempted. Putting aside the fact DPD just lied through their teeth about the location of a parcel containing prescription medication for a moment, why even do that? I'm going to be miffed if my parcel isn't delivered, but if there's a legit logistical issue I'm going to be a lot less miffed if they just tell me that rather than having their employees lie to my face, then cover their arse when called up on it. What difference does it make to them if they're honest about why they can't deliver? Either way I'm short a parcel but now I've also been lied to and will pay extra to avoid using DPD in the future.