Dr Peter Knapp was sitting in the front carriage of the train that crashed into the other service.
Despite injuring his leg and back he managed to open the door, disembarked and filmed footage of the aftermath of the crash.
He said: “The train exploded into this kind of frenzy; it felt to me as though it was a bomb explosion.
“Because I thought it was a bomb, I thought it important to get off the train as quick as possible. I managed to open the doors, but only I could get out.”
Steven Row, who has been a railway chaplain for 13 years, arrived at the scene on Friday evening and did not leave until 02:00 BST and praised workers.
“The adrenaline kicks in and the training kicks in and that high level of professionalism kicks in, but later on they’ll start thinking about it,” he said.
Row said he held regular well-being meetings with his team.
Tom Wootton, Mayor of Bedford Borough, said he was impressed with how everyone came together “in the most tragic situation”.
“People were helping, it was that type of wartime spirit,” he said.
“We just had to get on with it, and they did.”
He said doctors, churches, restaurants, taxi drivers and scouts all wanted to show their support.
Wootton told the BBC about a GP who had multiple injuries herself, but still stayed to support others.
He said a lot of people who had to get off the train that evening were not local.