If it's ice crystals they need to build up somewhere in order to cause downstream compressor damage. Internal probes may have served as a catcher for this very fast growth.
Interesting - I was writing a reply while you were giving a slightly "different" question.
Internal probe icing has contributed to downstream damage on other engines. However the 747-8 (and similar 787) GE engines incorporate probe heat basic on the internal engine probes that may be subject to icing.