That's a sort-of-misconception, I think. AFAIK the client has to "advertise" the general location of the standard buttons, so if it's generally well-behaved, bu

That's a sort-of-misconception, I think. AFAIK the client has to "advertise" the general location of the standard buttons, so if it's generally well-behaved, but just randomly locks up (via bug, not malicious intent), then you should generally still be able to close it. (That's my understanding from the pro-CSD crowd, I'm personally pro-SSD, so I may have misunderstood unintentionally, but I think I'm being as charitable as possible in the above interpretation/description.)