What tweet is he talking about?
He did an analysis of the claims Ford made and used them to posit a possible address of the home where this could have happened. He posted pictures of the home and a floor plan and related it to her claims. Then he identified the kid who lived in the home and noted that the kid looked a lot like Kavanaugh.
Basically, he set some other kid up as the perp.
In here. Gives address, posted pictures of the other man (since Twitter deleted), gives his name repeatedly.
https://freerepublic.com/focus/chat/3689357/posts?page=3
In the original tweet, now deleted, Whelan is speculating that the accuser misidentified Kavanaugh, confusing him with another classmate.
Creating reasonable doubt.
Even now as adults, they look amazingly similar.