"Where did you get that 'flight' fantasy ??"
Flight risk is not literally a flight as in aircraft flight risk - it means going somewhere else when you've been told to stay in a certain place. The Cambridge dictionary defines it as:
"someone who has been accused of a crime and is considered likely to try to escape out of the country or area before their trial begins."
Julian was told to stay at his bail address in the English countryside, but took off to the embassy in London.
C.