A guy that I met a few weeks back works for a competing private firm. It is his first job out of grad school and he applied for a position in another state in the public sector.
However, he casked one of his main clients to be a reference for him. To my knowledge, this client has only really had contact with him, but I thought it was kind of interesting. I know that clients are often willing to be references for the firm to find other clients but this is the first time that I heard of someone trying to use them as a personal reference.
My first thought was what if his existing employer found out that he is looking? Then my second thought was how will this change the dynamics of his relationship with his client? Personally, I thought it was a bit of a risky move... even more so if he doesn't get the job. If he was working for me, we would sit down and I would be bothered that he did not come talk to me first, but then I would do what I could to help him find a new job someplace else. I would not want someone working for me that did not want to be there. I wouldn't fire him, but I would let him know that his division to open the door is an indication that he might not be a good fit.