Back to the $2 note pair...
Again, the quality of the images makes it difficult to express an opinion with a high degree of certainty. However, on the larger note, I can see what appears to be an elongated crease running close to the top edge, and to me at least, this suggests that the top part of the note was bent over at some point. There does not have to be a hard fold as evidence of being in a bundle. The edge of the oversize note protruded out from the rest of the bundle and was likely bent over the top of the bundle. The serial number ending in 999 shows us that the sheet from which these notes came was the last sheet in a ream, and cutting errors typically happen on the first and last sheets in a run. For whatever reason, the first/last sheet became misaligned prior to a stack of notes being cut. It does not have to be deliberate, though one has to wonder how this kind of error slips through quality control without being detected, removed and destroyed. There will always be room for the "conspiracy theorists" to believe that these notes had "help" getting out of the printing facilities.
The serial numbers ending in 999 on both the $2 and $1 error notes points strongly to the possibility of accidental misalignment caused by the machinery. I used to own a 1937 $100 note with a cutting error showing an extra piece, and the note had a serial number ending in 000. I sold the note for a fair price, though in retrospect, I could have asked for about ten times as much had I tried to invent a story about it being the product of employee mischief rather than pure chance.
We have no idea as simple collectors if any sheets of older series notes were saved by the Bank of Canada and/or presented to important persons. We only know about those series that were sold to the public in uncut form.