Oaktree Capital Management Analyst interview questions

Received a timed excel test based on handling large amounts of data and outputting presentable/accurate information. Next was a standard phone screen with HR going over the typical behavioral questions. Last round was at the Oaktree office and consisted of 4 interviews with 1-2 people per hour. Apparently there's another round that involves interviewing with senior management if you make it through the first on-site.

I started by submitting a resume online, then they got back to me within a few days to schedule a phone interview. The phone interview was pretty typical - they asked about my resume and experience, and what I wanted to do. Soon after, they contacted me again for an in-person interview. At the in-person interview, I spoke with a few people that I would have been working with. It was very laid back and casual, nothing intense, and everyone seemed nice. They called back saying they "moved forward with another candidate" (typical corporate language), but that they had another Analyst position for a different team that they thought I'd be a better fit for. So, another interview was scheduled, and it was much like the first - met with a few people I'd be working with, and everyone seemed nice. For the record, both of these first in-person interviews were about 2 hours, talking to 4 people for 30 minutes each. Got called back for a final interview, this time scheduled for about 3 hours with 6 different people. A few of these people were in completely different departments and had nothing to do with the job I was interviewing for (and they even admitted this with a bit of confusion). Also, at one point, I was waiting for about 30 minutes between interviewers - it seemed someone forgot I was there. I was surprised, because up to this point, Oaktree had been pretty organized and focused, but this final interview seemed very fragmented and lazy. When I finally spoke to the hiring manager at the end of the process (who I had already spoken to in the first interview), he gave me a verbal offer - it seemed abrupt, yet appropriate, given the urgency of the role that was needed. I left the final interview with a smile, and thought my job hunt was over. But I was wrong - even though I received a verbal offer, Oaktree went silent for 2 weeks, then finally called me and told me they "moved forward with another candidate." More corporate speak, but this time with 10x the disappointment. Why would you verbally offer someone a job, then not follow through?