After submitting a paper for review, I received a letter from the editors containing a negative report and informing me that their (editors') decision was to reject the paper. Although the paper was about six months with the referee, it was clear from the report that she did not read it, just had a quick look and wrote a report, full of typos, mistakes and speculations about what the referee thought was in the paper (as she didn't read it).
I wrote a letter to the editor saying that I agree with their decision to reject the paper and would not dispute it. But I also expressed my opinion of the report, because I think it might help to increase quality of the review process. I had no intention to get the paper reconsidered, and even started to prepare a slightly revised version to submit it to another journal. However, they have responded that they would give it to another reviewer.
Now this situation is quite uncomfortable for me: I imagine how the referee will feel if the paper gets accepted and appears in this journal. On the other hand, the referee should be well aware of the (poor) quality of her work, so maybe she will not care.
The question is: should I care?
Most journals solicit half a dozen referees hoping that two or three will respond. (I'd be worried about a journal that only uses one referee.) In any case, referees do not usually know how many or who the other referees are, so the person in your case may assume that the vote was 2:1 against them.
In either case, the editor has absolute discretion. They've been known to override even majority negative reports and go with the .... (drumroll please).... minority report.