Having trust score of
0: -0 / +1 really not possible.

Why wouldn't it be? The "trust score" increases with time. A positive feedback (made today by Hhampuz) isn't going to score you any trust score. That's why the first digit is a 0.
Possible meh?
I though when someone got positive feedback from DT member they must attain trust score as well,atleast one.Because on many cases I have seen people with 1: -0 / +1 , but no profiles with zero trust score while having positive feedback.