Thanks, that’s pretty helpful. Looks like his ticket was purchased about two weeks before he was exposed, with plans presumably being made for some period before that.
I’m not sure how this works, but I would assume his paperwork, such as a visa, would need to have been started much earlier yet. According to this site, it looks like getting a visa would likly take up to three months or more.
http://travel.state.gov/content/visas/english/general/wait-times.html
I heard on the radio this morning (WCBM local conservative talk) that his visa, along with 13,000 others for Liberians was approved by the State department despite warning flags not limited to his country of origin (eg, never having been here before)
All that is to say (and the State department’s ineptitude aside) he clearly made plans well in advance of his exposure to come here.