I am pretty sure it was OK.

I went and double-checked. This is off the website:

"...(i) Subject to the restrictions in section ii and iii, you may freely distribute the maps you create using OUR ARTWORK in CC3 format, but not the source image files (PNG and bitmap artwork) associated with them. You may freely distribute flat files (for example BMP and PNG) exported from CC3 containing OUR ARTWORK. You may publish such maps for commercial gain."

Since I am not "distributing the source image files", I think I am OK.