I think we both agree that they took a big risk calling police. But one was injured (Misty) and two had their purses stolen (Misty and ...Brandy?...whoever). Consider for a minute that:
1) perhaps there was a lot of money in those two purses;
2) that money may not have been theirs;
3) they'd already made the purchase with the money and the purchase was to go to someplace else;
4) the fear of returning back to that place empty-handed was greater than the fear of getting in trouble with police, because there was nothing they could really be arrested for, it gets on the record that they reported a robbery, and could buy them some time to spin the tale back where it really needs to be spun.
I could go on with the theoretical. But as someone says in their sig-line: If there's stink, there must be hink. And this one smells all the way over here.