I ran with a guy last night on a duty roulette that couldn't hold hate well at all. He flashed A LOT and still had trouble. I think there's a certain mix that needs to be done depending on what you're fighting and who's in your group, and not a "one and done" strategy that will always work. I've yet to play a tank, but i'm a pretty solid DPS for my level and I pull aggro off tanks often. Most of the time i'll just slow down on my combo to keep it on the tank.

In short, i'm saying just because the tank has aggro doesn't mean the DPS aren't gimping themselves to help the tank keep said aggro, and I doubt just spamming flash will always keep the hate on the tank.