I can’t answer your question.
I believe there is a fault (or perhaps it’s bad design?) that means comments are deleted when a problem is hidden. So even if the hider did leave a comment, it would have been deleted.
You may get an answer if you email the admins on contact@spoj.com, but it’s not likely to be a quick one.
Edit: I see it’s now visible again - did you find out a reason, or who was responsible?