Good question,
It is what you wrote lets say I give you positive feedback now and then get added to default in 5 months, your trustscore would then be 5-0/+1 and as you said the longer it is left the higher the score regardless whether I was on default at the time of giving you the trust or not.
Ah thanks for the answer, locking this thread, don't think any of my feedbacks are gonna appear as trusted anytime