I actually see it as a good sign--the T is willing to risk your anger in order to protect a child. To be honest, I agree with your T in that this should be your nieces' own work and words. I'm not saying that your intentions were not good ones. But is there a possibility that you have things you want this guy in jail to know (maybe your anger at him at how he has affected his niece.)

So it is a good thing your niece has at least 3 adults looking out for her.