Yes, I do believe it is always a good idea to tell the truth. Yes, there is a difference between being a team player and a whistle blower. The difference to me is a team player goes along with what is best for the team. A whistle blower is someone who does what is right even if it is bad for the team. A whistle blower and a team player can be the same when someone does what is right and it is good for the team.
I have confronted bosses before. I did this because it was the right thing to do. I know that this can have varied consequences. I have been written up, denied promotions and even let go because i didn’t compromise my stand.