To be fair, I don't think anyone is really taking this seriously. Or, at least, they shouldn't be.
I read what J. Alex Halderman wrote about it. He says the media is misrepresenting his position. What Halderman is arguing is that PAPER ballots are preferable to systems that use only digital information, simply because it makes it possible to verify results in the event that hacking is suspected.
Halderman is not suggesting that any hacking was done in this election. He merely wants to shine a light on the potential risk with information being exclusively digital. He said it would be a good thing if a candidate demanded a recount because it would highlight this point about digital vulnerability. His interest is strictly in cyber security. He did not himself make any claims about foul play in the election or espouse any partisan stuff at all.
If this story builds, it will just be another instance of media sensationalizing and taking advantage of a climate where people are riled up and eager to read & absorb provocative stuff right now.