Everything out of CTV, ie CTVHDE, CTVHDW and TSNHD, Discovery HD etc are sent out in 720 to BEV and 1080 to rogers. SO, yes, when CTV airs CSI in HD, they are degrading the signal.
If you watch it on CSBwest (seattle) it may or may not be in 720. Depends on whether CTV HD West in Vancouver is...