Congratulations on buying the book, you are on your way to enjoying this great hobby.
Great question.
Bank notes are not produced at the mint, they are printed at the printing companies, Canadian bank note Company or American bank note Company.
Yes it is very possible that employees at the production companies could pull out notes, but I highly doubt that this practice occurs at that stage of production these days with the tight security, as this practice would jeopardize the agreement with the Bank of Canada, as every single serial number would have to be accounted for.
I am sure the Bank of Canada requests that certain notes be pulled for their files or testing.
Yes it is quit possible to determine where a number would lay in the run. The printing companies knows the exact calculation of where a note would fall, so would be very easy for them to find. Scan the forum, and you will find articles about the sheet layout and numbering.
I have heard that a few special numbered notes are pulled out by armored car services employees often. I am sure this may be a grey area of their employee agreement, but not for me to say. So this would mean that yes special serial numbers notes can be found by the public.
Coming across special serial numbered notes is rather difficult, but very possible. Just don’t think you are going to find them all the time from your pocket change.
Finding special serial numbers notes are usually found when a person has access to a large quantity of notes, and with constant searching. But still, it may be years before you find something like a solid or ladder note. Radar notes are more common, and from time to time you will come across a replacement note.
Finding special serial notes in circulation is very tough, so your best bet would be to order new and seal banknote brinks at your local bank (there will be a change for this service).