Looks like the 4chan story may have been an anonymous post by the "DNC strategists" to play this out and tell the public that claims on the chans are unreliable. They love making anonymous posts and anonymous threatening phone calls that appear to be coming from the other side. It's a standard part of their schemes. Good example – the NV 2016 D primary that was a mass of fake claims of violence, terrible behavior, projection, and anonymous threat phone calls.