If the OP makes his victim whole, he should have his trust issues resolved. Although as I mentioned, I think the chances are high that this person engaged in similar behavior in the past.
You are not allowed to spam referral links in forum posts. Sending a ref link in a PM is acceptable, as long as you are not sending an unsolicited PM.
In this case, OP sends the affiliates link via PM. I hope OP will clarify if that guy was agreed before he send the PM.
If someone receives an unsolicited commercial PM, they should report the PM. If the OP has a single infraction of sending unsolicited spam PMs, they will likely receive a warning from a mod without a ban, or at worst a temp ban lasting a few days.
For the record, the feedback I left wasn't simply because of a single unsolicited pm with aff link. It was the pm plus behavior in the thread I mentioned:
https://bitcointalk.org/index.php?topic=5382115.0 My issue is not necessarily with the OP sending spam PMs with referral links. My issue is with the OP promising to pay someone 1 LTC in exchange for signing up via his referral link, the victim accepting the offer by signing up via the OP's referral link, and the OP not following through on his promise.
The referral spam is certainly annoying, but is not something I would agree that negative trust is warranted for. It is the OP not honoring his promise that I believe makes the negative trust appropriate.