I'm inclined to believe that he did want to serve, and that he is indeed (justifiably) pissed about being turned down. If nothing else, serving in the war would have been a huge boost to his political resume.
Buyers should have fought the decision, if necessary by resigning from Congress. At the rate things are going, the war will soon be over, and he could have been home in time to run for Congress in the special election to fill his own vacancy.
But if he did it I might look the other way.