Since this has become relevant again with the media taking Zack Snyder's quotes out of context and many notable creatives taking issue with Snyder based on the deliberately misleading articles I'd like to add my own contribution. I'll give Bruce the benefit of the doubt and assume he simply dodged out of the way of the rock and didn't throw it since apart from his hand gesture nothing could support this in my mind. With that said him dodging allowed the rock to hit the guy and when he blew up Bruce didn't even flinch. So this idea that Bruce values all human life so highly including a criminals seems misinformed. Also he admits to killing in the next image.