it seems that btcjam primarily forbids direct confrontation with borrowers, knocking on their doors and shouting "pay or else ...", and the like:
Lenders may not post pestering or threatening messages on any listing.
So the focus seems to be on extra-legal methods, it would be strange to ban legal methods.
Another point is, that you have already won the arbitration, which I guess supersedes the rules for lenders. In other words, I would argue that arbitrator has (or should have) taken rules for lenders into account.
Yet another point could be lack of cooperation and explanation from btcjam.com.
For enforcement, see
http://net-arb.com/FAQ.php#Enforcement .