That's how the trust system works. It's far from perfect, but it's not the end of the world if you get negged by a member who isn't on DT.
Hey, you still don't get me. I don't give a damn to a person who isn't in DT and gave a negative trust, what I am worried about is, any of these guys can go into DT and the same moment it will be seen as a valid 'yet invalid' red trust by someone from DT. So, these people who don't know what this trust system is for, need to be taught a tough lesson to make everyone aware that trust is not a manor that these guys can keep in their pockets and pull out whenever they feel comfortable.
Putting them in my distrust won't do anything except to me when I will watch my profile. I had no connection to these people, still I personally messaged them and humbly asked those who gave me negative trust but I think they've got a big enough EGO which didn't get satisfied by my request. So let them have it kept there.