I'm inclined to go with Mriya225 on this one. While an interesting hypothesis, I do not believe that the missing spacer contributed to this accident in any significant way. The analysis of the speeds, times and distances along the runway tend to suggest that performance was not in any way inhibited until the aircraft hit the metal component.
What is of interest is the allegation that this crew disregarded an eight knot tailwind. Perhaps this needs looking into, but I find it hard to accept that professional investigators have dismissed such a fundamentally important issue, especially when it seems the suggestion is that there is some powerful political influence at work to make them do so.
I guess time will tell. But in the meantime I must say I find the article somewhat offensive, especially where it implies that the skipper was a natural born risk taker. I still have nothing but the greatest respect for that crew and nothing but utter sympathy for their impossible task in trying to make the unflyable fly.
I also happen to think that the early rotation may well have been a selfless act of stark heroism.