Seymour Hersh is not credible anymore. This is all based on a single anonymous source, that hasn't been supported by any other sources or evidence. He is known to have just made stuff up to suit, which is probably why the NY Times and other papers passed on this and he had to put it on a new substack.
https://www.vox.com/2015/5/11/8584473/seymour-hersh-osama-bi...