Your Game Master may accept to waive such prerequisites if your background or in game actions justify it. Unlike normal Feats, a Prowess can be acquired several times.
Against all odds, your character manages to run away from a perilous situation.
No matter how well guarded or restrained he is, he will manage to unlock his chains and jump out out of a window unharmed. Several accomplices will be there to help.
Or maybe he is at a disadvantage in a battle and someone on a horse will miraculously come to his rescue and ride away with him.
No matter the situation your character is in, he will be able to escape unarmed within few minutes as if he had the help of several accomplices and enough time to plan this evasion.
The evasion is not instantaneous, it does take couple of minutes, so it cannot be used to avoid an arrow. But it can arguably be used to run away from a crumbling building.
Also, it helps your character run away to a safer location, but won't cure him of existing conditions.
If the game master agrees, not only your character but other friendly characters can escape as well.