I'm seeing plenty of responses that aren't wrong but they're forgetting that these situations are more than just doing your job well. As a member of a team, it's also your job to contribute to the team. By making it harder on a teammate you're not doing as good of a job as you could be. If you're a dps ripping hate from the tank before they get to their place for combat, not good. If youre a healer taking away their enmity by over healing or using certain skills mid pull, not good. We're on a team and must behave as such.