OK guys, I might have pinned down a location for the tax collector. I went to the same spot and same time as this dude in the video (credits goes to GameNitedotNet). I made sure to also hide so as not to scare the collector before I could see him.
SPOT : Haggia Sophia tunnel entrance.
TIME : Bank deposit trigger.
First time, nothing happened. Must be because there are 3 bank deposits in an ACR day : daytime, evening, night, with 20 min between each.
But the second time, the collector also appeared on my radar at the exact moment when the bank deposit triggered. He was coming at me from a different direction than in the video, but still, there he was.
And yes I had completed the game and locked all my dens, and no I wasnt in full awareness. So neither one is a requirement.
Edit : Since a very few people still seem to have a hard time, I'll list a few more tips mentionned in the comments.
- Make sure to hide
- To some people he appeared 2-3 mintues after the deposit, so stay sharp.
- Pay close attention to the radar, since he comes from a random direction.
- If you fail and he dies, exit the animus and come back in, just to make sure he doesnt keep any "dead" status.