Just for us non-techy types that are following this thread with interest, can I just try to clarify how the nacelle anti-ice system works?
Is it that there is a pipe or pipes that bleed air from the third stage of the high pressure compressor in the Trent core and bring it forward to the annular leading edge of the nacelle? Here its inherent heat (due to it having being compressed) is used to ensure that ice does not form in the nacelle inlet.
Presumably the hypothesis therefore being raised is that at some point along that pipe(s), which presumably run between the nacelle liners and the cowling's external skin, an explosive failure occurred which had the effect of blowing out the nacelle/cowling material on either side.
If this is the case, then presumably the internal lining material was blown inwards and thus inevitably through the fan, although from the photographs this shows surprisingly little evidence of damage.