I took it to mean POTUS didn't know anything about the Assange case, ie he wasn't involved with the DOJ prosecution.
He obviously knows about Wikileaks, he only said it a thousand times on the campaign trail, so he could just be trolling the fake news, knowing they would jump all over it and it would bite them somehow later.
Could be that, or he's just trolling. Distancing himself from the extradition to make whatever Assange says (like SR gave him the info) seem nonpartisan.
Who the hell knows, the man's 73 and has the energy of a coked up terrier, there's bartenders and jihadi janes in Congress, I've supported Lindsey Graham, this timeline is all over the place!