The imposition and enforcement of disciplinary punishment under this subchapter for any act or omission is not a bar to trial by court-martial for a serious crime or offense growing out of the same act or omission and not properly punishable under this subchapter. However, the fact that a disciplinary punishment has been enforced may be shown by the accused upon trial, and when so shown shall be considered in determining the measure of punishment to be adjudged in the event of a finding of guilty.