Yes, for example there's a coroner who rarely gets to the scene of the crime before a person dies. There are witnesses who tell all manner of things that never 'eye-witnessed' the crime.
Yes I know that. There are religious witnesses too.
But I was referring to people who have earlier seen something, as in
"The police spoke to eye-witnesses."
The guardian was running a series on journalistic cliches, of which there are many, you'd be surprised.
How many times do you hear "sneak preview"?