At that point, just don't have biometrics configured at all. It would be waaay to easy to accidentally wipe your phone. Just have an unlock PIN and a duress PIN

At that point, just don't have biometrics configured at all. It would be waaay to easy to accidentally wipe your phone. Just have an unlock PIN and a duress PIN. You're going to be charged with destroying evidence either way if you use the duress method, so you may as well use the method that won't accidentally wipe your phone with a single misplaced finger.