Again, this is false, obviously so.
I don't think so. DarkStar's reply makes perfect sense, maybe re-read it again =)
Taking your example: "Suppose there are two investors, A and B, and each have 50 btc onsite and 50 btc offsite. A is lying about it but B isn't."
A 50 BTC loss to A is 100% loss of their bankroll, but a 50 BTC loss to B is only a 50% loss. This drastically changes things as a margin call to A is fatal, while B would just be looking at replenishing their onsite investment.
I'm sorry, haven't both A and B lost 50 BTC here? So aren't both -EBG? And hence it doesn't matter whether your offsite is real as to whether you'll be +EBG or -EBG? And hence, like I said, Daniel's and DarkStar's claims are simply false?
Maybe let's try this another way: Suppose I invest 50 BTC onsite and 50 BTC offsite. Will I be +EBG or -EBG? And if your response is to ask me "Are you lying about your offsite" then my answer is "I'm not telling you." So go on, will my investment go up (+EBG) or go down (-EBG)?