I dont know how he , or what he has reported ! But with the amount of reported posts and threads that there are 704 unhandled is bit crazy.
Maybe there should be a overthinking about the reportingstyle and things about how he is doing.
Sometimes its also a reason how you report it and what you write in there.
Here are my reports:
You have reported 19035 posts with 100% accuracy (18930 good, 41 bad, 64 unhandled).
More speculation: If you are reporting posts that are old when you report them, your report may not be high on the priority list.
If you doing that they can marked also as unhandled and maybe you will get a message from a Global Mod as i have done that when i started.
Depends also on what you reporting.