Like everyone else I am not privy to what went on in the flightdeck that night. However, it would surprise me if the crew were not aware of the weight of the aircraft. It would have been discussed during the flight plan review, during the final fuel decision & passed to load control for the load sheet.
The problem as I see it, is that the weight was incorrectly entered into the laptop in what appears to be a simple typo. Then, for reasons not yet known, the error was not picked up on the cross-check of the laptop. Nor did the V-speeds look wrong for the weight, to 4 qualified pilots. If this does turn out to be the case, no amount of weighing the aircraft & delivering this weight to the crew would have prevented the accident in Melbourne.
Perhaps an SOP, that in this procedure simply required one crew member to check a bunch of figures entered into a computer by another crew member, is not an adequate error trap, particularly considering the serious safety impilcations of getting it wrong. I would have thought that with what is now known regarding human error, particularly in regard to aviation, that a more robust method of error trapping for this critical aspect of flight preparation would have been devised & formalised in the SOPs.
That being said, this accident hopefully will serve as a warning to all flight crew of the serious nature of the business & how quickly & easily it can bite you. It is certainly a sober warning to me of the need to constantly review my performance & the need to ensure that if I am required to cross-check something that I actually do a thorough & deliberate check, rather than just glancing over it because I am busy, distracted or tired & it has always been correct in the past.