Editorialist: In all cultures, it is almost universally accepted that one has a moral duty to prevent members of one’s family from being harmed.
Evidence
In all cultures, it is almost universally accepted that one has a moral duty to prevent members of one's family from being harmed.
Intermediate Conclusion
Thus, few would deny that if a person is known by the person's parents to b falsely accused of a crime, it would be morally right for the parents to hide the accused from the police.
Conclusion
Hence, it is also likely to be widely accepted that it is sometimes morally right to obstruct the police in their work.
Evaluate
The gap in the reasoning is that there may be a moral duty to prevent members of one's family from being harmed, and also a moral duty to assist the police in whatever capacity one is able.