I'm not really sure what argument is failing. I'm certainly blaming the leaker for using bad opsec (sent emails to The Intercept using a work computer). I'm also certainly blaming The Intercept for using bad opsec. I'm also pointing out that the government has every incentive to act like it was The Intercept's bad opsec that allowed them to find the leaker even if they, for example, found who it was by just looking at access logs for the document.