Rather Be Flying,
I`m not sure if you appreciate that there are TWO possible drills for the fuel leak case.
1. If the leak can be confirmed as coming from the engine then it calls for a shut down. Once that has occured the X-Feed can be opened because it is upstream of the LP valve and should not therefore pump fuel under pressure through the leak.
2. If the leak cannot be identified (probably likely in their situation) then the drill says keep X-feed closed and descend to gravity feed ceiling which in their case would be FL200. Once reaching this level ALL pumps are turned off in an attempt to minimise the fuel leak.
It would appear what they did was keep both engines running at altitude, which is rather like doing a bit of both drills.I figure if they had done EITHER drill completely they would have probably ended up doing a SE approach and landing.
Just my fourpenny worth.