When (and if) I run a flashpoint, I will run ahead and I will pull things. Why? Because I tend to have more health than the current tank as a DPS. I kill things fast enough that tanking is not necessary. I typically run with a healer from my guild that is capable of 2manning it.
Now, why would I sit around and wait for a tank to take his time and pull everything, when I could just do it for him and finish the place in a fraction of the time?
Then DO it alone.
And stay away from GF, my "all-mighty" friend.