Honestly, I initially even missed this moment.
Here is how it looks to me now. The guy calls, waits on the line for a long time, then says, "I spoke to you privately. My brother..." and GH enthuses, "oh yes, the election!" And then the guy dumps all the info about very little DNA, and then GH asks, how the election went, and the person says, successfully, and GH says, you were always such a reliable source.
What do I think. The election was maximum for the local library trustees, sorry.
If this dude had a brother who won a major political election in Indiana, even in Delphi, and the said brother was such a blabber that he told intimate details of the Delphi case to his brother, then there was no better way for the said (loving) brother to reassure no future reelection, than to call GH and dump it all out.
So - either GH inflates his sources (very possibly), and unsurprising,
Or, this leak is approved and hence, valid.
My take: I am 50% positive that there was too little DNA, and 50% positive that someone intentionally made the scene contaminated by dumping different sources of DNA to make it extremely mixed. Both would achieve the same effect.