Speaking of just reading the headline, The Intercept piece you linked has the facts wrong, apparently relying on readers like you not having read the original Guardian story.

1. There is photo evidence, but the Guardian cannot publish it for one reason or another. They described the clothes he was wearing that day in detail.

2. There is an entry in the guestbook for him, it doesn't come up when you ctrl-f because they misspelled his name, it appears as "Paul Manaford".

This isn't "lack of transparency", it's protecting your sources.

But, then again, I wouldn't expect The Intercept to know how to tell the difference, seeing how they've burned Reality Winner and Terry Albury.