Okay a few things to note, it is about 3am, so it is dark, and the guys running away do not disappear 'on the horizon', they disappear almost immediately into the darkness and the neighborhood. They also did not get a good look at the van, because it didn't arrive immediately on the scene, it was right on the end of Fionn's perception.
Other issue, Sammy can visit a clinic all she wants to, but unless she is moving in it won't help her much. Because Heron used magic to save her, first aid can't be used anymore. But yes, she can wake up.