The problems of memory and oral transmission Ehrman brings up to undermine the Gospels’ reliability are undercut when you realize that not that much time had passed when the accounts were committed to writing by the people who witnessed them. These were astounding events, which tends to burn things into memory. The events were also shared by many people, which helps support accurate memories and details. And the eyewitnesses began relaying these events to others very shortly after the resurrection. The Holy Week details were part of what they taught over and over from the beginning. And Luke interviewed many people for his account so he was able to get corroboration from various eyewitnesses.