No they would not.
Since WW1 the rules regarding the following of lawful orders is somewhat different.
The Armed Services Act states that orders must be lawful,
"Unlawful orders are not to be given and are not to be obeyed. Members of the UK Armed Forces must obey all lawful orders issued by a superior.
An order to commit an obviously criminal act, whether given directly or indirectly, such as the torture or other mistreatment of a prisoner, is an unlawful order which does not relieve a subordinate of his responsibility to comply with the law.
The possible defence that a subordinate was only ‘following orders’ will only succeed if the subordinate did not know, and could not reasonably have recognised, that the order was unlawful. Such circumstances are likely to be rare.
Where an order is capable of being misinterpreted, a subordinate must seek clarification. Where an order permits such degree of latitude to a subordinate that it is capable of being carried out lawfully or unlawfully, it should only be carried out lawfully."
In a civilian situation the civilian law would take precedence and unless there is some serious changes to legislation and a complete retraction from UK law of the auspices of the Geneva convention then what you seem to be suggesting simply would not take place.