...
>I cannot figure out why the copypool would ever have more data in it
>than the primary pool.  Any ideas?
...

The most simple explanation would be that the copy storage pool was the
target of a primary storage pool other than what you expect, at some
time in the past.  You can perhaps most readily pursue this by looking
into Occupancy values for the various nodes and filespaces which
participate in that copy pool.

    Richard Sims