No way out as far as I can see my friend...
I suspect the 3 DMCs are sourced from 3 different busses and hence design limits on probablity of failure achieved.
We Know that does not mean it cant happen!
AAIB Bulletin: 9/2009
6 February 2007 at 1146 hrs
Location: En route to from Barcelona to Liverpool
check out the above AAIB report from the web