When they attacked him in his home, he did have a right to defend himself. But shooting the woman as she fled, that's hard to justify. His comments aren't exactly helping his case either, especially suggesting he shot her twice to "send a message" to the man who escaped. The only reason you shoot another human being is out of legitimate fear of death or grievous injury to yourself or another.
Neither one of them would have been shot at if they weren't breaking into other people's homes. There's the true culpability.