Omnicell Finance/Acctg interview questions

Applied online. Then talked to the recruiter. The next step was hiring a manager. It was going well or so I thought until I mentioned I used to work with someone from her previous company. The conversation basically was done and she made up her mind. Got a rejection and when I reached out to ask why? The recruiter said the manager said I was not a good fit. I mean, we talked for less than 30 mins how can she tell I was not a good fit already, especially when she spoke negatively about her previous employer, and I told her I used to work with that person.