Is cost/return a factor in these things? I'd hope not. If expense stops prosecution, the offender can learn where the cut off lies, and just offend below the benchmark. Somewhat like the way I drive (speed camera goes at 10kmh above limit, I drive at just under this).

A rough approximation off the graph: volume before the announcement ~190,000. The announcement pushed the price down by ~$0.30/share, so by trading before the announcement, they avoided losses of ~$57,000.