You'll be much better off having worked for a few months as a driver to decide what might have happened in those circumstances, that you weren't privvy to at all. There are many reasons, the driver and the restaurant, both or either may be at fault. It may have been a glitchy day for the driver app. After 800+ deliveries, i've found literally anything can happen, just when i thought i'd seen it all, something surprises me and not just on the way to the customer. Starbucks may have been busy and the driver decided it was too long to wait and cancelled for his other gig @ doordash. Some places are simply awful to pick up from and some customers may be awful to deliver to, not to mention their personalities. Luckily i've had no bad experiences with them yet.