How does he know that Glitter Draw Free was the culprit?
It's well known that APNS tokens are not unique on a per-app basis, even though the documentation says they might be. [0]
The theory that the leak didn't originate with the FBI is totally plausible, but I don't understand the connection with Glitter Draw Free, and I suspect the email's author doesn't realize that APNS tokens are not unique.
0: http://stackoverflow.com/questions/2338267/is-the-apn-device...