me_irl

From what I read it was more that the First Officer was worried that his body might damage flight controls or engines if they let him go. Probably both.

There is a similar story from 2018 where a passenger was partially ejected from a damaged window after a critical engine failure. She got pulled back in by passengers and flight attendants but later succumbed to her injuries. Interestingly what killed her was blunt force trauma from being smashed against the outside of the cabin due to the violent nature of the explosive decompression, not the enviromental circumstances of being on the outside of a plane travelling at cruising height & speed.

Although your chances of surviving that for a prolonged time are slim at best I would say. Captain Lancaster was just very very lucky.