I've read many assumptions on the motives of this individual who has questions for you. Many people have real and valid concerns with how the church has controlled the narrative of it's historical accounts. It has hindered their faith in the organization. Obviously I don't know the individual you are speaking of so I can't comment on their actual motives, but in my opinion the LDS church has done it's members a disservice by providing plenty of "milk" but no "meat" in regards to historical and doctrinal topics. I was actually just speaking with a couple institute professors regarding this very subject recently and they voiced the same concerns.
Having read many books and papers from a variety of historians, authors, BYU professors ect. on both sides and in-between (Bushman, Compton, Quinn, Hales, Palmer, Smith, Van Wagoner, Hancock, Barlow, Gordon to name just a few) You'll find that the standard church approved rhetoric regarding a variety of topics is not exactly what it seems. Some will simply read information on these topics from a variety of authors and find the analysis of the accounts "faith promoting" and others will find them detrimental to their belief in the church. Personally I don't find FAIRS to be the most objective source for material. Not to say that the majority of answers to questions from them I believe are invalid, but (in my opinion) I find more mental gymnastics needed to accepts some of their analysis-I'm just more of an Occam's Razor kind of person I guess so I'm willing to accept my own biases.
I find that the church is one group of individuals attempt to understand spirituality and the divine. It's organized and run by mortals with many flaws. To believe that the church and it's leaders simply rolled through the last 175+ years without making small, medium and large mistakes is....well, naive.
My advice would be to read from many of the authors listed above and begin to form an opinion for yourself. Don't make it a battle with the individual, show empathy and love for them. When you have a better understanding of the topics then discuss it with them if desired.
My 2 cents anyways...