Making innuendo jokes to a friend is not sexual harassment either. If he had said, "hey want to see my big dongle?" to the girl, that would be harassment because he would be making unwanted sexual comments towards her.
However, he just made a joke to a friend in private, and she overheard. I'm allowed to say anything I want to my friend, even if it may be inappropriate for the setting. She was free to think of him as a jerk, or even tweet "there's a jerk behind me." (Although I don't think there's anything wrong with making an innuendo joke to a buddy, but clearly she does.) Unfortunately, publicly shaming the guy for a private comment not meant for her was totally uncalled for and puts her on the wrong side of this mess.
I stopped in a local donut shop a couple weeks ago and there was a patron with his child that was horribly offended that the shop had a TV in the store and it was turned on (to some benign news channel) without even the volume on. I could tell it was one of those crazy people that don't even want their children to even know TV exists, he kept going on and on about "I can't believe they would have a TV." Long story short, the fact that you're alive will offend someone.
In this case, I don't believe Adria was offended. She is inauthentic to me.