I would approach this assignment by being myself. If it offends me, it probably offends a group of people. I would try to approach but acknowledging that people may not be aware of the problem with the work but then I would state facts to support my claim that it's culturally offensive. I think it is important to address the issue directly because the respect for other people's culture is what makes society function. Moreover, this would allow the readers of my review to be educated in something that they may not know anything about.
The following people is an example of an unreliable narrator would be D. Edgar Allan Poe; however, he is also the author of "The Tell-Tale Heart".
Poe's unreliable narration comes from his personal background of turmoil and suggesting to the readers that they think that he's mad, and make presumptions behind it.