Jamal Jivanjee is, like Ergun Caner, a real ex-Muslim. He has testified to the fact that he went to the same Muslim "mosque/ masjid" as the Caner family (link to testimony). Some of those supporting Ergun Caner have viewed this as complete vindication of Dr. Caner. There are a couple reasons why it is still incomplete.
a) Mr. Jivanjee has not identified what years (even approximately) it was that he witnessed the Caner family at the "mosque/ masjid." This is not significant to the question of whether the Caner family was Muslim, but it is significant to the question of how devout they were.
b) Mr. Jivanjee has not testified as to whether Ergun and/or Emir were devout when he knew the family. Indeed, his testimony suggests that he may not be able to say, since he may have known them only slightly (he remembers as a young child eating dinner with his family at the Caner house) and/or he may have been too young to remember that kind of information.
Those items are what we would like to see from Mr. Jivanjee. I had previously asked Mr. Jivanjee if he knew Caner when Caner was a Muslim (link to my question). Mr. Jivanjee has not responded to my request. I have also asked the author of the blog that has reported Mr. Jivanjee's comment to see if he can elicit any additional facts to help support the points above. The information above would help to provide evidence against the Muslim critics who have been alleging that Dr. Caner was never a real Muslim.
However, it should be noted that the Christian critics of Dr. Caner have not been arguing that Dr. Caner was never a Muslim. Instead, the Christian criticism has focused on a variety of autobiographical embellishments, from claiming to debate people he never debated, to claiming to be born in places he wasn't born, and to have lived in places he hasn't lived. None of those issues are addressed at all by Mr. Jivanjee's comments. Thus, I think Mr. Guthrie is too optimistic when he writes: "Liars? No"