It's possible that the time difference between the Shards and Source is more dramatic than we thought and sometimes time can seem to flow backwards between them, though that's convoluted. A simpler explanation would probably be that someone in Amdapor had a vision of the future. Whatever the case, I recall Alphinaud mentioning at one point that he wanted to investigate it so I expect we'll see something mention it in-game even if it's not a major focus.