Granted I'm only a four-year guy but I seem to remember that there was some leeway when not in uniform. The letter is to be read at the end of Mass. Therefore, he is not in uniform but wearing the stole. Am I stretching or is this an out for the Chaplains?
Speaking of leeway, the story of Catholic Chaplain Otto Sporrer's action at Chosin Reservoir indicates that Chaplains can turn themselves into combat commanders.
And so it must be that chaplains have some leeway as to what they really are: under God's command, common sense command, or Obama's command.
Chaplain Otto Sporrer was awarded a Silver Star for taking command and successfully leading American forces in an extreme retreat situation. That action is mentioned in the book telling Chesty Puller's story.