It is absolutely normal for a company to offer you a position and change their minds
thereafter. Often times have nothing to do with references because strategies can change over night and line managers may change their minds on hiring for the position. I know this because I am a HR professional and this has happen to me several times when i was looking for a job personally.

I think lets not quick to make assumptions and lets be kind to one another and understand that the job hunting is a very stressful and often time lonely process. A person offered a position and then had that position removed from them can lead to a variety of emotions.

To the original poster please don't give up and be disheartened. I hope you get a job soon and all the best!