Well, when I was back in Canada, I too would spend/pay with $5 notes. That’s how I was able to advance up the board. Locally I became know as the $5 guy. I would even be asked if I “had change”, people wanting to break larger bills. Seems, as we all know, the most common bill used these days is a $20 (except for us dedicated trackers😉). I even had one place that would actually call me, asking me to bring smaller denomination notes.
Go shopping at Costco and pay in all $5 notes. Not hard to drop a bundle while shopping there. They didn't mind, actually appreciated it so they could get the smaller denomination notes.

So, what I'm saying is, he wasn't/isn't the only one.
I actually loved spreading stamped $5 notes during my travels. Always use them for tips in hotels/bars etc.