that might explain GLP, but not OSOCA (the link in the first post)- his indictment indicates the emails were obtained and read while he was still under investigation, before he was arrested.
The only thing that would explain OSOCA is a compromise of hushmails implementaion of PGP, a keystroke recorder on OSOCAs machine that captured his passphrase, or that he was sending cleartext emails from hush to non-hush recipients.
the official open-source verifiable version of PGP doesnt have to be compromised or have a backdoor, only Hushmails implementation of it. As far as I've read, it doesnt look like Hush has any 3rd party independent audit/confirmation of the version of PGP they use and how they implemented it (mods, tools etc).