Actually your son was not totally incorrect. True, the Maple Leaf flag is our current flag, but both the Red Ensign and the Union Jack have been used as our national flags. Here's a quote from the Canadian Heritage Government website:
"The original Royal Union Flag, or Union Jack, was first raised in Canada at the British settlement in Newfoundland after 1610. Although the Red Ensign was widely used in Canada from the time of Confederation until the national flag was adopted in 1965, the Union Jack was the affirmed national symbol from 1904 and was the flag under which Canadian troops fought during the First World War. The Union Jack maintains its presence in Canada through its incorporation in the provincial flags of Ontario, Manitoba, and British Columbia."
But our UK contingent might point out that strictly speaking your bag is not quite an accurate representation since the white cross bars look to be the same size on either side of the red cross bars. My third-grade teacher back in the late fifties used to make us draw the Union Jack in art classes; anyone who didn't do it EXACTLY right had to stay in at recess... Some injustices never leave us!
Oh, I almost forgot, both of your outfits look fabulous: simple, but strong.