3M O2 Engineer interview questions

Applied online and was contacted by a recruiter by phone for an interview. This went well (mostly behavioral questions, why the position, why the company, applicable experience, etc), and I was invited onsite the next day or so for an interview about two weeks later. There was no warning, but a few other candidates for the position were interviewing the same day. The day was composed of a lunch and plant introduction, followed by (depending on your schedule among the group) a plant tour, a process-specific tour and interview, a peer interview (EHS and QC engineers), and a behavioral interview (recruiter and plant manager). All the interviewers were very open to discussion on specific topics and appeared generally engaged and friendly. They responded very well to good questions. Being personable and interested along the way seemed to help in the process and helped me make a good impression. I received an offer by phone the day after.

Round 1 was a phone interview with basic behavioral questions. Round 2 was on-site. They let you know beforehand that you'll see your competition, which was only one guy. More on him later. There's 2.5 interviews and a tour. Both interviews are with plant managers. Standard behavioral questions. The interview after that is with a couple guys who recently went through the O2 program and there's no set questions they ask. They take you on a brief tour. Up to this point I had no problem with the interview process. But what happened afterwards, not so much. The interview was on a Friday. They told me I'd hear back from them next Monday or Tuesday. This never happened. I followed up with an e-mail a week after the interview, and no response. It wasn't until almost a month later that I got an e-mail saying that I didn't get the job. This part I'll try to say with as little ego as possible: I was able to talk to my competitor before the interview and he had a master's degree with (as far as I could tell) no experience. I have a bachelors, two internships including one in manufacturing along with five years experience in another industry. My non-technical skills also blew his away. I'm not sure it's relevant, but he was a middle-eastern guy (I think) while I'm just a white guy. So the guy with better academic credentials who could tick the diversity checkbox beat the guy who had tons of actual job experience.