Some of the issues raised in their second debate were addressed in my review of their first debate, and I won't be repeating everything I said there. Mike Licona made a lot of good points during the second debate, particularly with regard to his research on hallucinations, but I won't be reiterating everything he argued during the debate. I recommend watching it to hear all of Licona's points in context. What I want to do here is expand on some of Licona's points and bring up some other issues he didn't discuss.
Ehrman criticizes Licona for acting as a theologian rather than a historian in some of his argumentation. But Ehrman's claim that the resurrection has such a high initial improbability depends on his theological assumption that particular entities capable of performing a resurrection, such as God, don't act in history. As Licona noted, though with different terminology than I'm using here, agnosticism doesn't get us to Ehrman's conclusion that a resurrection is so highly improbable. The unlikelihood of a resurrection occurring naturalistically doesn't tell us how likely it is that God or some other entity would raise Jesus from the dead.
Even if we concluded that Jesus' resurrection is highly unlikely upfront, the evidence for the resurrection can be such that it overcomes that initial improbability. See Timothy and Lydia McGrew's article here for a discussion of some of the principles involved.
Ehrman frequently mentions miracle accounts in other belief systems, such as the purported miracles of Apollonius of Tyana and Marian apparitions, and he did so again in this debate. He didn't argue that the evidence for such miracles is sufficient by Christian standards, and he didn't argue that the miracles didn't occur. He just asserts that there's sufficient evidence for those miracles by Christian standards and asserts that the miracles didn't occur. But he needs to argue for both. Christians, such as Mike Licona's mentor Gary Habermas, have addressed such non-Christian miracle accounts frequently and sometimes in significant depth, and a Christian worldview allows the possibility of miracles among non-Christians. Ehrman can't just assume that the non-Christian miracle accounts in question have sufficient evidence, and he can't just assume naturalism. He needs to argue for both. If a Marian apparition, for example, is inconsistent with what we know about hallucinations, then Ehrman needs to do more than assume that something naturalistic occurred and replace the word "hallucination" with the word "vision". Such a change of vocabulary, accompanied by an assumption of naturalism, isn't an argument. It's an evasion. If Ehrman can't adequately explain the evidence for Marian apparitions, in addition to not being able to adequately explain the resurrection evidence, then bringing up the Marian apparitions doubles his problem, in that sense, rather than eliminating it. We've addressed Marian apparitions and other miracle accounts often raised by critics of Christianity elsewhere on this blog. See the relevant links in my review of the first Licona/Ehrman debate, linked above. When will we see Ehrman offer a comparable treatment of the subject?
As Licona noted in his closing remarks, Ehrman is wrong about the phrase "the twelve" in 1 Corinthians 15:5. And there's much more evidence Licona could have cited. Group names like "the eleven", "the twelve", or "the apostles" are often used when it's known that not every member of the group is present. Thus, John refers to "the twelve" when he knows that Judas has already left the group (John 20:24), as does Paul (1 Corinthians 15:5). Craig Keener cites similar examples from non-Christian sources, such as Xenophon and Plutarch (1-2 Corinthians [New York, New York: Cambridge University Press, 2005], n. 272 on p. 124). Retaining the number twelve as a group title would be particularly significant in this context, since there's so much significance in a parallel to the twelve tribes of Israel (Matthew 19:28). Paul knew that Jesus had been betrayed (1 Corinthians 11:23), and accounts of Judas' betrayal of Jesus are widely reported and unchallenged early on. Luke's gospel refers to the betrayal, and Paul cites Luke's gospel as scripture in 1 Timothy 5:18. (Even if Pauline authorship of 1 Timothy is rejected, the document would still be evidence of a high view of Luke's gospel in early and influential Pauline circles.) The idea that Paul was unaware of Judas' defection in 1 Corinthians 15:5 is dubious. Ehrman often relies on such bad reasoning in the process of claiming contradictions among the Biblical accounts. His use of that sort of argumentation reflects more poorly on him than it does on the New Testament.
At the start of the audience questions segment of the debate, Ehrman argued against the use of scribes in composing the gospels by claiming that the early sources who comment on gospel authorship don't mention scribes. Actually, some sources who had access to the writings of Papias claim that he was a scribe of the apostle John. See the Codex Vaticanus Alexandrinus 14 and the Anonymous Catena On John here. 1 Corinthians 16:21 suggests that Paul was using a scribe in the composition of that letter, yet Clement of Rome comments concerning 1 Corinthians, "Take up the epistle of the blessed Apostle Paul. What did he write to you at the time when the gospel first began to be preached?" (First Clement, 47) Paul is seen as the author of 1 Corinthians, even though the letter itself refers to his use of a scribe. We know that Paul used a scribe in the process of writing his letter to the Romans (Romans 16:22), yet Irenaeus (Against Heresies 2:22:2, 3:13:1) and other early sources refer to Paul as the one speaking in Romans, without any mention of the scribe. The use of scribes was common in antiquity. People often refer to somebody as the author of a document even if he's known to have used a scribe. The fact that the four gospels are attributed to Matthew, Mark, Luke, and John doesn't tell us whether scribes were involved in the process. Similarly, we today often refer to what the head of a company or a politician said in a particular document, even if one or more other people participated in the drafting of the document. Ehrman's argument against the gospel authors' use of scribes is unreasonable.
His treatment of the argument from martyrdom is misleadingly selective. It's true that the earliest sources don't refer to Peter's being crucified upside down. But we do have earlier references to Peter's suffering and martyrdom, even though the upside down crucifixion isn't mentioned. See here for more about the martyrdom argument and the inadequacy of Ehrman's objections to it.
Much more could be said, but I've covered a lot of this ground in previous reviews of Ehrman's debates. We have a lot of material on Ehrman in our archives, if any of you are interested.
It doesn't seem that Ehrman's argumentation improves much from one debate to another, even though the arguments leave so much room for improvement. He spends a lot of time traveling, debating, speaking on the radio, and such, but he doesn't seem to spend much time reconsidering his arguments or researching his opposition.