[Ken H]

Take a close look at the liquid that was tossed. You can see that it almost reaches the cops, to the left of the girl. Further, they all initially turn to the left in the direction of the liquid, but the girl is to their right.

She turns to the right, and at that point the cops and the girl have their backs to each other. They are all reacting to the liquid.

[Uncle Chip]

You can see that it almost reaches the cops,

But it doesn't reach them does it??? And what happened to the string theory???

All 5 cops turn at once and look right at her -- no one else??? Whatever they were reacting to came from her. They didn't hesitate or look around for anyone else. She said something that was the last straw.

And she like the guilty party turns to run.