The lump of metal from the DC10 was definitely the prime cause of the accident. It was a titanium rubbing strip, about the size of a 1-foot ruler, from a thrust reverser. It was designed to be easily replaceable because it got rubbed in normal use. The part that fell off was rather crudely made and was not an OEM part, but the book said you could make one yourself if you wanted to. I am not sure if it was supposed to be made of aluminium and someone had made a titanium one to get a longer life out of it or whether they are all made of titanium.
This one was always going to be a lawyers' benefit but I would be rather surprised if individuals are to be charged at this stage. It would be difficult if not impossible to prove culpability at this stage. Company lawyers seeking damages from othercompanies is another matter.
I don't believe that the missing spacer on the U/C had much to do with it and the aircraft was not overweight. It was right on the limit, and that did not help. It had a long taxi, and that didn't help as the tyres would have heated up. However, it was the lump of bent titanium that sliced up the tyre and threw big lumps of rubber up that really did the damage.