I was stood at the Ford chicanes watching the final 3 hours, the cheer from the Porsche Experience building could be heard above the GT race engines. From what I have read the root cause of the problem was a cracked carbon fibre turbo inlet manifold, that resulted in the turbo failure on the Toyota.
Good to see that the ACO and FIA saw sense and did not exclude the Risi Ferrari for it's lead lights not working correctly. They were told to pit to fix them after Ford protested during the race, then shown the black/orange flag ordering them to stop and fix it, they ignored them. Earlier during the race both Porsche and Audi were allowed to race with their cars showing the wrong positions for about 2 hours without being hauled into the pits for repairs.