said by Mike_C:
The DNS and the peering have nothing to do with it. It's YouTube screwing around with their website, servers and infrastructure.
You do realize that DNS and peering are a major portion of "servers and infrastructure," right?
DNS often plays a significant role in deciding which CDN servers a client connects to. Which CDN server you connect to affects the routes the traffic will travel across. The idea behind trying different DNS resolvers was to try and end up at a different CDN POP, to perhaps avoid a potentially-overutilized peering connection between Telus and the nearest CDN POP.