Now, as I recall...
The BoC use to receive banknotes unsigned until about 1968. They would imprint the signatures themselves. After 1968, the signatures where either added to the engraving or litho'd on. Beattie served 1955 - 71 and Rasminsky early 60's - 73 so their in the right range. The O/R would have been an "early - mid" range prefix, so it's at least conceiveable that it's a setup note for imprinting that got flipped over.
What I don't like is the colour change. As Tom says, a good loop would help.