wdmw's Kill was ethically and statistically supportable; if you go through the rest of the rounds, you will see this. Thus, future traders should treat wdmw as an ethical trader; and to treat him otherwise will be viewed poorly by the Alliance.
Black market justice has my back!
But you are now forcing me to keep my security...
No coercion here. Free to do as you please!
Let it be known we are a just and merciful Alliance. As always, there is a "bounty" to restore yourself to neutral status (where you will be treated from then forward as an "ethical trader" until you again prove differently). In the rules of this game, the Alliance enforces ethical trading a certain way. This is because there are only two choices, Trade or Steal (aka Kill), and no option to, say, "decline to meet" or whatever.
So, in order to "pay off the marker" on you (you personally, based on your current "ethics balance"), you must allow your partner to choose Kill whilst you choose Trade, TWICE. Once this occurs, you will be eligible for the same protections the alliance offers to its members, should you so choose.
The kicker is, you may be "blackballed" by ethical traders in the following way: If you do indeed choose trade, but your partner also chooses trade, you will have traded; and this does not decrease your "marker" value (2 in your case). That is of course somewhat of a dick move on the part of the ethical traders, in the sense that you are trying to make good and they aren't allowing you to repay your debt; but, it is met and largely prevented by the chance that, you might have decided to NOT pay down your marker and chosen Kill again: in which case an ethical trader will have been again killed unethically, increasing your marker further! So in the event that you have a net debt, it is in your best interests to choose trade; and it is in the ethical traders' best interests to choose Kill, until balance is restored.
Note: Do not confuse this with wealth redistribution or socialist concepts. The Alliance makes no distinctions regarding who has a poorer balance of points and does not try to have points restored to any particular individual. The Alliance exists merely to protect against unethical trades by providing a method of tracking "unpunished, unethical Kills" as a balance to be corrected in a future trade with *someone*.