I really don't want to be the parade rain-er, but caution definitly has to be excercised.
As soon as tellers have access to it, things can happen. Now, from what it appears, your notes might be the real McDeal.
However:
a) tellers often slide notes out and count them, and then put the BoC bands back on them. Some do not realize that BoC sometimes do not need to be counted. What I am saying, is that BoC bands on single bricks does not really mean anything unfortunately - since they even re-use them sometimes.
b) counting = mixing possible.
c) notes get split all the time.
Now, the fact of the matter is that there may have been tampering. If you can get your hands on bricks (sealed bricks of 10 bundles) then the information can be taken as though it is truly out of a virgin brick.
For you sake, I hope someone else has been able to confirm your find. I know what it is like to have a find that doesn't get confirmed.
Fingers crossed
PS: Welcome to the site, I am sure you will find it most helpful.
Hudson