"Staying off of private property is good advice in any country, he says, it's just that in America, the risks can be more severe."
Given that it was dark, in Texas, the invader would be without any legal recourse (though in Montana he is still dead).
If Kaarma had called the police, the burglar wouldn't have had any legal recourse either.
He would have been convicted, jailed and then deported.
And Kaarma would be a free man to boot.