No, as I understand it, the Predator ship crashes in Colorado, and the predator(s) are sent to clean up the situation, i.e exterminating aliens and witnesses. If someone was allowed to escape or capture Predator technology, humans could study it and it'd make future hunts more difficult.

Much as I am loathed to use it, but, in Predator 2, he tore through a train on a killing spree. But you later find out, he only killed the passengers who had weapons, yet there were several witnesses to that event who were not killed.

Also, from the trailer, its not clear whether or not the humans had been facehugged.