Interesting question, and hopefully one that remains a "what-if".
There must be some JAG types floating around FR to opine on that...
I am a JAG (former active duty/currently USAR). This is nothing new. Every combat arms brigade has an assigned JAG that deploys with the brigade and provides legal advice on military justice and operational law. For the most part, he works out of the Brigade TOC. Just another staff weenie. Under no circumstances does a JAG veto any targeting decision by a commander. The JAG merely makes recommendations and the final call always belongs to the commander.