"If the crew are medically fit to assist with the investigation into the accident, then immediate access might well prevent recurrence. For example, if the cause was due to a problem with the airport approach equipment, then identification of this must surely be of the highest priority.
The crew can still refuse to answer a question that they feel might incriminate them, until "professional" help arrives, whilst permitting useful information to be gathered by the investigators."
Newswatcher
It certainly would be ideal for folks to just let out with everything they know. However the Buzzards on the Fence (Lawyers) are in the wings waiting for an honest and slightly incriminating statement. You pay for representation, you had better use it.
As the Duke said. "Life is Tough, but its Tougher if your Stupid."