It's actually horrifying reading some of the nonsense that has been typed up on this thread!!!
First & foremost, it was definitely NOT a blade out, as anyone who has witnessed or inspected an engine which has thrown a blade; & I have only seen engines of much lower power capabilities which sustained this type of event; will show that the inlet & fan, plus casings, is totally catastrophic & beyond any repair, not to mention tail cones shearing off, gearboxes breaking their mounts etc etc, yet the engines still amazingly do generally contain all deadly potential missiles that result from this. They are manufactured & certified to do just this.
However in this case, the fan blades & rubstrip area appear in a beautiful condition totally void of any serious hardened metals or titanium fragments ingestion.
The blades apparently did have a few nicks & marks on some, naturally caused from the ingestion & chopping up of all the acoustic lining plus the outer carbon fibre material of the nosecowl, being sucked into the fan. At T.O. power settings they would have no choice but to go through the fan!
Also "apparently" this engine was only brought back to Idle power due the surge or parameter shifts, & remained at idle normally for the return & landing! If anyone can confirm this I would appreciate it.
My assumptions go along with Gaspath, I think, who said it most likely is a nose cowl inner barrel acoustic lining failure, for what reason no one is yet sure..... ingestion of FOD or material break-up?
I have my doubts about NAI as the supply duct enters the nose cowl at the 7 o clock position which is practically 180 degrees opposite to the panels that have been blown-out/sucked-in? those running around the right hand side of the cowl!.
Most definitely a nose cowl failure, whatever the cause.