He fly into the US, when through Customs, and had a valid Visa. And maybe the hospital should have thrown him out in the street to fend for himself. Can see any harm coming from that, huh? You can blame Reagan for that one, thanks to EMTALA. Damn socialist!
Except when misrepresenting your health status, including knowingly lying about exposure to deadly infectious diseases, gets your visa revoked. So it was obtained or executed under false pretenses. Sorry. Defend it all you want, he knew, he lied, and he should have stayed away. What he did was a criminal act that endangered the lives of millions of people and may have directly caused the death of who knows how many... time will tell.