With respect to the dueling over 767 capabilities, people just don't seem to be paying attention to what is being written.
What Airsupport has been saying seems pretty well OK to me. "Immediate return" does not mean running down the cabin screaming "we're going to die" (OK, literary licence there) .. It just means - "let's land". As he said, some 767 aircraft don't have dump capability, and as far as I can remember, no 767 has the capability to dump to Max Landing Weight when at its Max Takeoff Weight.
Back to the topic ....
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