I am still noob to Trust thing.
First
Why can't i see his profile like this , it didn't appeared red flagged to me untill i gave him neg rep , and even now it just shows
-6: -1 / +0(0)
Warning: Trade with extreme caution!how exactly does this Trust works ?
Check who is in your trust list. Put in only DefaultTrust to see the default setting that most people see, though I don't recommend using that and recommend adding/removing people who leave accurate/inaccurate feedback.