Ah okay, rookie mistake then. I've only done development myself once while using someone else's facilities. This roll was bought and developed at my local lab, though I did scanning myself. I just assumed that the box iso of 3200 was to be trusted. I'm not sure how they developed it tbh, but I assumed it was okay because the edge markings looked way denser than the highlights in most photos. And I assumed that the edge markers are exposed for 3200 iso too.
I probably just overexposed the hell out of this picture, which is why it did turn out fine. Turns out that 3200 iso means that it becomes pretty hard to shoot in broad daylight with a fastest shutter speed of 1/1000th. There are quite a few photos which seem to be ridiculously underexposed.
This photo, for instance, was DSLR scanned and converted with the exact same settings as the one in the post:

It's possible to get a bit more out of it by adjusting the settings, but obviously you can't make information appear that was never recorded by the film. I even took a second shot with different settings because I wasn't confident about my settings, but both shots are completely nuked. Even the sky isn't middle gray
Awesome! I only noticed that it was happening just before I wanted to go to bed, and I wrongly assumed that I had to use long shutter speeds which ruined most of my shots. But I got something decent from my balcony at higher iso and faster shutter speeds. I also have some with red but I missed focus on all of them.