I was just curious, not being provocative. I think the rule is way less than clear. You spend a lot of time in GBU and I thought you might have an opinion on it. If not, no problem.
I do have an opinion. By the letter it looks like feedback should not be left. But that doesn't seem right. I don't think there is a clear answer here to be interpreted by members. My opinions is to ask a mod and do what they advise. They would likely talk it over and come to a consensus, might even include spark.
The OP did do the right thing so far: start a thread here! Seasoned BF members know to look here when considering who to deal with rather than just relying on itrader which is but one indicator as to who might be a concern.