Indeed, my 'theory' comment was a response to an infected case arriving on an airplane - which this is news story is an example of.

I'm only aware of these cases (are there others?) Hence, I used theory until you've had a few more occurrences.

The first link in the previous comment documents:

1) 1996 a man in Gabon travelling to Johannesburg and he didn't infect anyone.

2) 2004, a man with Lassa fever, similar to Ebola, travelling to the US and not infecting anyone.