While the most lurid aspect of those stories was the child sex part, there are a lot of other implications of that whole disgraceful saga.
The actual ethical issue was that as a "journalist," he paid sources for his stories. That's a cardinal ethical principle in journalism, and Eichenwald flagrantly violated it. Think of it as like the legal ethics principle that you can't pay witnesses to testify a particular way. If you do that, you lose your license forever, and you'll be lucky to avoid prison. If journalism actually had any ethics, Eichenwald's career would have been immediately terminated forever. Instead, this snake is still slithering around.
Then, there's the specific issue of lying about seizures to try to cover his other lies. Even if you assume he's not lying about that, it would still mean he's a severely mentally ill person who probably still shouldn't be a journalist because he apparently can't remember anything, so his reporting is obviously going to be incompetent and inaccurate.
If he ever does take the stand in this case, he should be cross examined vigorously about this whole child porn affair. Either his testimony is unreliable because he doesn't have a functioning memory, or it can't be trusted because he is a pathological liar.
He can't even adhere to the most central ethical principle of journalism, and that's his actual job.
Oh, plus I'm not sure he's a pedophile, but he definitely has connections to child pornographers, has given money for the production of child porn, and he definitely totally looks like a pedo.