Just found this while looking to see if there was a law in Colorado requiring someone to step in and help having been a witness to a crime such as this. I was unable to find anything to that effect, but, found this interesting...
It is illegal to assist a fugitive in any way. Accessory to Crime, CRS 18-8-105 Colorado Law states:
"A person is an accessory to a crime if, with intent to hinder, delay or PREVENT the discovery, detection, apprehension, prosecution, conviction or punishment of another for the commission of a crime, he renders assistance to such person." This crime can be up to a Class 4 FELONY, punishable by up to 8 years in prison and/or a fine up to $500,000.00!
Taken from:
http://www.springsgov.com/Page.aspx?NavID=3438
So the dip***t that told the girls to get out of there before the cops got there was preventing the discovery of these two worthless individuals, therefor committing a crime himself. I would hope that MD has the same kind of law and that this punk will be prosecuted.