Ehrman position is that the writers believed that the followers of Jesus believed they saw Jesus. This belief does not translate into an actual first hand account of the event.Even Erhmann agrees the disciples believe they saw Jesus after the crucifixion. I just saw him in a youtube debate last week. As a historian he just can't say a miracle occurred.
If a mass hallucinations occurred, people could have just checked the tomb or internment site for the body. People weren't anymore gullible then than they are now, Surely someone could have checked.
If we had to rely on first hand, real time, eyewitness testimony, we would have to give up the academic discipline of ancient history. Herodotus was not an eyewitness to the Greco-Persian wars, but he is our best source of information about them.
Having someone who intimately knew the eyewitness disciples and reported what they saw and told him is a good primary source for historical scholarship.
Peter and James were still around when Paul was writing letters and doing his mission work. If Paul were lying about what they told him they would have heard about it.
Paul chose to live a difficult and dangerous life, facing shipwrecks, pirates, and prisons. I don't think he would have risked his life for lies he supposedly put into the mouths of the disciples he knew.
I think an NDE is the most rational explanation that comport to the facts.
There is a lot of speculation surrounding the Gospels, but the bottom line is the Gospels were written by anonymous sources 30-100 years after the time Jesus supposedly lived.