Nielsen-Kellerman Embedded Firmware/Software Engineer interview questions

After applying for this position through LinkedIn, I was contacted several days later to schedule an interview with the resident Senior Software Engineer. This interview was straight forward; a few behavioral question about career goals/ resume details and then technical trivia questions. These questions were fairly high level and I was able to answer them all successfully to some degree. The interviewer was very pleasant and astute, knowing what could be expected of someone with my experience level. Hours after the interview, the recruiter emailed me and told me they would like me to come in for an interview. She also wanted more info on relocation needs and salary expectations. I replied, accepting the interview. I also gave her my salary expectiations, saying that I was flexible. It was a week before I heard anythng back. She replied that they had "unexpectedly" hired an existing contarctor 5 days previous and wished me luck in my job search. Needless to say, I thought this was very unprofessional, not somuch for canceling an interview, but moreso for leaving me hanging while they hired someone at almost the exact point they offered it to me, and also for not even having the heart in the email to say they wouldn't be pursing me as a candidate (this was only implied by the extraneous hiring story and thanking me for my time).