An answer is an answer I guess. My original plan to animate the flipping domino by animating the pivot has fallen on hard ground. After attempting it, then googling it I have found that it isn’t really possible (at least in this version on Unity 3.5).
Some people have developed a C# script to allow the moving of the pivot to bypass this limitation. However it’s not really what we need.
I’ll need to animate it manually, or in Maya first.
So, on to plan b.