Cisco Software Engineer interview questions

Went through a phone screen, followed by a onsite visit, where I talked to 3 pairs of engineers, and the hiring manager. The interview went well by all accounts, and the manager asked for my references the next day. Upon contacting my references who said nothing but good things about me (this is beyond any doubt), sent me a rejection email citing fleeting "team fit" reasons. At no time during the interview was there any discussion of collaboration styles etc. To add insult to injury, he wasted not just my time but the time of my references; you just don't ask for those until you're ready to make an offer. First time I got a rejection after getting my references checked in my entire career... highly disappointing.