It's kinda funny that with this, when they can't think of what is going on, the first conclusion they jump to is "time traveler talking on a cell phone". Obviously Ockham's Razor is not the most well-known thing to a lot of people.
Lots of things in this world is fishy, and trust me the human brain is a powerful thing. People can force themselves to believe almost anything. Aside from that, I'm sure there is quite a reasonable explanation to all of this. Hell may have already been a known reasonable explanation to this that has just been left out. Wouldn't worry about it too much.