An additional head-scratcher is the loss of control of Engine #1 throughout all this (from Aviation Week):

"The airline has determined that another Trent 900 engine on a different A380 requires replacing, according to a source with knowledge of the inspection process. Damage or abnormal wear was discovered in a similar area to where the uncontained failure occurred in the Singapore incident, the source says.

Also, there is discussion about whether the no. 1 engine on the Singapore aircraft (VH-OQA) needs replacing, according to the source. This engine could not be shut down automatically after landing, possibly due to damage to wiring in the wing caused by debris from the no. 2 engine. The engine eventually shut down due to foam sprayed by emergency services."