Your References when job searching

I am employed and this has noting to do with me right now. There has been a few times where I have heard that someone was very willing or offered to give references for someone who is job searching. Later, the one who is job searching, cannot figure out how they never landed a job that was made for them. My co-worker, "A" was looking to move to another department and couldn't figure out why she was not getting jobs. "A" is a very good worker, very quick and very accurate when she does her job. Also, she is very sweet, pretty and a very nice person who was also kind with me when I was having a hard time at work. Later, with another interview, one of the managers took her aside and told her not to use "B" as a reference because he was not saying a good things about her. "A" was floored because he offered "B" to be one of her references. When I was told about this, I was shocked, but I have heard of this before and happened to me once also several years ago. What I don't understand is, what makes a person say yes or offer to give references and then they lie and give a very poor reference? Has this ever happen to you? I also understand that you can sue the person who gave you a poor reference, but how do you prove it? I recall when I was unemployed, other people I've met had one experience like this. We all tried to recall if we ever did any wrong doing to them and this was not the case. I would really like to know what makes a person do such a cruel thing? Have you ever given a bad reference?

Put the internet to work for you. via Personal Recipe 2629984