So you are saying he should ask for trouble?
Actually, from a criminal law standpoint this is one of those things that you'd think no sensible prosecutor would care about. If the self-defense is legitimate then it shouldn't matter if you used a battle ax or a punt gun or a kitchen sink. Whatever is at hand should be fair. The problem is more about the prejudices against gun owners in some jurisdictions. If you defended yourself with a handload in Utah, or in most of Texas or Wyoming, it shouldn't be a problem. If you did it in New Jersey, NYC or Boston, though, I'd not be sanguine about the handload issue not being brought up. I'd call your local prosecutor's office and ask how he feels about what ammunition CCW permit holders have in their weapons, and let his feelings be your guide from the standpoint of criminal liability.
Then the other issue is whether or not the criminal or his family will sue you in civil court. There they only have to convince a simple majority of the jury that you had malicious intent.