The reviewer is, in most of the cases, an expert on the main subject of a paper, but his or her is not the only expert in the field. The author of the paper could be also an excellent expert in the same field.
If the author of a paper disagrees with the opinions and evaluation of a reviewer, then he/she has the right to present his or her arguments using scientific facts to support these arguments.
I had the experience that in some cases the evaluation made a reviewer was incorrect and reflected some ignorance of the subject under review. I reject his or her evaluation given the necessary scientific arguments to sustain my position. The editor, in almost all cases, accepted my arguments, and the papers were finally published.
In my experience, as an author and as a reviewer, there are times when two reviewers' feedback can be quite contrary. Editors have recourse to invite a third reviewer. In responding to a reviewer's comments, where I maintain my position about what is written, I think that part of a robust professional and academic dialogue includes giving clear responses - that is, making points rationally. At times, such dialogue might also be useful within the publication, acknowledging divergent views, but recognising the usefulness of such a debate.
I felt quite irritated when the reviewer (an excellent chemical engineer) of my paper written on a new, advanced way of automatic control of an important manfacturing process dismissed it on the basis that automatic control of the process was already in use in the industry. I was irritated even more, when this reviewer of a prestigous journal added that he has absolutely no familiarity with the subject. The end result: the paper was not published.
In my opinion the reviewers should stick to a simple (but elementary) rule: if you are not really familiar with something to a rightly expected level, it is better not to fool around...