Headlands New Grad Quantitative Researcher Interview Experience — An Amsterdam Dinner Led to a Fast OA, Then 40 Minutes on My Resume

I'm a rising senior at a UK undergrad program. Over the summer, I got invited to a dinner in Amsterdam by Headlands, which is how I first learned about the company. I applied for the Amsterdam QR New Grad role, and the process moved really fast: applied 7/26 -> OA 7/28 -> first round interview 9/8.

OA:
18 questions. 10 multiple choice questions covering probability and statistics, hypothesis testing. Questions 11-15 were written-answer questions about stats and regression. Questions 16-18 were coding (one was mandatory in C++ — I study physics and had no idea what I was doing, so I just skipped it, didn't expect to pass anyway). Overall it was a lot easier than I expected, nothing too hard.

First round:
The interviewer was a research dev from the NYC office, a veteran from HRT and DESCO, but he was super nice! He opened with a 10-minute self-introduction that honestly left me kind of lost, then spent a full 40 minutes going through my resume — he dug into two strategies I'd listed, and since I didn't really have much alpha to show for them, I guess I ended up explaining pretty deeply, which ate up a lot of time. Only near the end did he remember he was actually supposed to test me on something technical, so he rushed through one pretty interesting hypothesis test question in the last 10 minutes:

There are five possible colors of M&Ms. Suppose someone claims that, purely by taste, they can identify the color of an M&M. There are 5 colors of M&M.

1. The person tastes three M&Ms and correctly identifies the colors of two of them. Is this convincing evidence that they can identify color better than random guessing?
2. Suppose instead that the experiment is repeated with 100 M&Ms, and the person correctly identifies 40 of them. Is this more or less convincing than getting 2 out of 3 correct?

I felt pretty good about the interview afterward, but it's been almost a week now with no response, so I'm guessing it's a rejection — from what I've seen on the forum, if you pass, you usually hear back for the next round within a day or two. It might also be because I mentioned upfront that I don't know C++, which feels like the only real issue. Overall the experience was good — things moved fast and the interviewer was really nice.