Why are we reluctant to call Ts?

[stripes]

You'll notice that I put my whistle in my mouth to call the T as my partner says he would handle it. Didn't think I could let my partner walk coach back to the bench and then I give him a T, IMO would further destroy what credibility my partner had left.

MO about Ts is that they are like any other call, if the criteria for calling them is met, call it.