In The Myth of Persecution, Dr. Moss repeats the assertion that martyrdom is used as proof of the truth of the martyrs' views. For example at page 43 she states, "The notion that her innocence is proved by her death is uncomfortable to us, but it is the same idea that we saw with Socrates: individuals' worth and the truth of their claims are irrefutably proved by their deaths."
Likewise, at page 17 she poses the question: "Why would the apostles have been willing to suffer and die for Jesus if he hadn't really been resurrected from the dead? Why would early Christians have been martyred if Christianity weren't true?" At page 23, Dr. Moss puts virtually the same words in the mouth of her divinity teacher.
At page 80, Dr. Moss states "the adaptation of paganism into Christianity threatens the idea that Christianity alone has the truth. Those who reject the classical tradition for religious reasons and hold Christian martyrs in high esteem tend to ignore Greek and Roman antecedents to martyrdom." Likewise, at page 81, Dr. Moss states "The problem is that this isn't what Christians have said about martyrdom. They have said that it is unique to Christianity, thoroughly new, and a mark of Christianity's sole possession of the truth. Christianity is true, it is said, because only Christians have martyrs."
At page 137, Dr. Moss states "The result of this is that the fact of the apostles' deaths cannot be used as evidence for the truth of Christianity, the resurrection, or any other detail of Jesus' ministry. We know that the apostles died, but how they died, on what charges, and in what manner are far beyond our grasp. Without that information it is impossible to state that their deaths prove anything."
At page 250, Dr. Moss states "In Christian terms, if you're being persecuted, you must be doing something right. It's a rather easy trick: if anyone can claim to stand in continuity with the martyrs and be victims of persecution, and if being persecuted authenticates one's religious message, then anyone can claim to be right."
These form a seemingly central aspect of Dr. Moss' book - her argument that martyrdom doesn't prove anything. Yet martyrdom does actually establish the sincerity of the martyr. It's not infallible, to be sure. A person may suffer martyrdom because they are suicidal, rather than because they really hold to the forbidden view.
Dr. Moss is definitely correct in rebuking those who argue "he died for Christianity, so Christianity must be true." But that is certainly not the right way to appeal to the martyrs. J. Warner Wallace is an example of a more correct use of the argument from martyrs (link), although I would point out that the source reliable historical information about the death of the apostles is canonical Scripture.
Almost none of Dr. Moss' arguments would respond to Wallace's usage. The one argument that might apply is this one: "The result of this is that the fact of the apostles' deaths cannot be used as evidence for the truth of Christianity, the resurrection, or any other detail of Jesus' ministry. We know that the apostles died, but how they died, on what charges, and in what manner are far beyond our grasp. Without that information it is impossible to state that their deaths prove anything." (p. 137)
It seems that Dr. Moss has forgotten about the martyrdom of James.
Now about that time Herod the king stretched forth his hands to vex certain of the church. And he killed James the brother of John with the sword. And because he saw it pleased the Jews, he proceeded further to take Peter also. (Then were the days of unleavened bread.)
Likewise, Dr. Moss seems to have forgotten about the prophecy of Peter's death:
He saith unto him the third time, Simon, son of Jonas, lovest thou me? Peter was grieved because he said unto him the third time, Lovest thou me? And he said unto him, Lord, thou knowest all things; thou knowest that I love thee. Jesus saith unto him, Feed my sheep. Verily, verily, I say unto thee, When thou wast young, thou girdest thyself, and walkedst whither thou wouldest: but when thou shalt be old, thou shalt stretch forth thy hands, and another shall gird thee, and carry thee whither thou wouldest not. This spake he, signifying by what death he should glorify God. And when he had spoken this, he saith unto him, Follow me.
Or perhaps Dr. Moss simply does not trust Acts (she seems rather uncertain that the author of Acts is Luke) or John.
It's difficult to say what her argument is, on points where she offers no argument.