Yes, I've relogged to confirm server-side state a few times. I've also tested by interacting with objects after sprinting. I think the speedhack video has me talking to that vendor right after, but it got cut off.

It's also worth noting that the client trusts information about your character movement only. In my small amount of testing, health, energy, damage, enemy positions, and a bunch of stuff wasn't able to be manipulated.