you are pathetic.
The guy who told you ten second has done a mistake ok, but it is necessary to wait before to DPS even if you DPS with the DOT.
The problem is you do some assumption from your observation without knowledge of the classe.
Moreover, the run back tehnique is not bad or good, The tank pull the mob and, if you wait before DPS and you move correctly, you will not have any problem.
In this forum and in the french forum a lot of people try to explain, however each time we try to explain you something, you do not want to understand.