I'm guessing he knew he'd been exposed to the virus and thus was at high risk of getting the disease. He also knew that he would have a much better chance of surviving if he was treated in the US. It was a perfectly rational, albeit utterly selfish, decision on his part. It makes me wonder how many others might try this if they have the resources. We probably should deny entry to anyone originating from a high-risk country. The stakes are just too high.