Yeah, we can test it easily. I know Lance has at least a couple of sock accounts he uses for testing; we could test on one of those, for example. But do we need to now? If I'm following this correctly, the reason to do so is to discover whether one of us released the fact we can read PMs. Right? But even if we can demonstrate that the members couldn't figure it out from the time stamps, I don't see how we can prove it was one of us - unless we read the email and PMs of all of us.
I have a problem with that. We only read members' stuff if we have reasonable grounds to suspect something - and then only the PMs or emails directly related to the reasonable suspicion. I would want at least the same standard for all of us. So, this would be one time we might want to let sleeping dogs lie.