It would take an unusual combination of factors to leave the aircraft in the situation it is pictured in if there were no failures, therefore I'll throw my best Sherlock Holmes in to the mix...
Presence of steps at the rear door suggests engines shut down, also spoilers 1/3/5 extended. Now, having at one point made the mistake of shutting down after landing but forgetting to disarm the spoilers, my experience is that all the spoilers stayed up and in order to retract them, it required the Y ELEC pump on with PTU left in auto (that sorted 1/2/4/5) then B OVRD to retract 3. If one wanted to only retract 2/4, that would require both engines off (to avoid B operation), Y ELEC pump on and either PTU OFF, inhibited due to certain criteria being met, or green system failure.
The logic diagram for the PTU suggests that it should run the G system if the Y pump is run on the ground with both ENG masters off, and the NLG shock absorber extended (which can't be clearly seen but best guess is that the nose gear looks like it's still properly extended).
In a roundabout way, and at the risk of being told to wait until the facts come out etc. how about the following as an armchair guess?:
- Aircraft lands normally, ground spoilers all extend.
- Aircraft vacates runway, all spoilers still up, then before 'after landing' actions take place (inc. disarming spoilers) suffers G system problem (LO LVL, LO
PR?) and therefore loses control of steering.
- Skids to a halt in the position shown given the slippery conditions. Crew runs through the ECAM, inc. PTU off, decides to shut down in situ, performs the after landing/parking checks but for whatever reason misses the check of spoilers disarmed (lever sitting up only slightly, small note on the ECAM memo lost amongst other items relating to the failure?)
- After shutdown, crew becomes aware of the extended spoilers and decides to disarm the lever and run the Y ELEC pump. This has the effect of dropping spoilers 2 + 4 only.
OK, I'll don my helmet but if nothing else it does the grey matter good to think about the system architecture, I certainly can't come up with too many obvious scenarios that would lead to an aircraft parked half on the grass with spoilers 1/3/5 extended.