Probably most of my online purchases start with trying to figure out where the package will be shipped from so that I can factor in import taxes to the EU. Surprisingly many webshops don't indicate their business of location clearly.
Likewise for shipping time. I need it by X and will not order if it's going to arrive later. That one isn't as much of a dark pattern as it's rarely done for deceptive reasons.
I can see people who shop like this accidentally hitting "purchase" every now and then.
They decided to ignore my cancellation and ship me the thing anyways. Now we're in a pitched battle over who should pay to fix their mistake. Regardless of the outcome, I'm never going to buy anything from them again.
I was super confused when a tool I had looked at three weeks prior turned up at my house.