The long version, is that if a program appears on a US channel and Canadian channel, the Canadian channel can ask to have the US feed substituted for the Canadian one (so far, I think on only Rogers and Shaw owned stations ask). Shaw is good,or bad, in that the substitution happens in the receiver, not the uplink. In your case that Canadian channel happens to be on G1, as it is likely a BC or Alberta station, add in HD when G1 went into service.
I am in Ontario, so many of the substitutions are on Toronto HD channels Shaw already carried in HD (mostly on F2).
But I am in Ontario, so get G1.