When I look at the situation that Artiste went through, I see an education being paid for (Lord knows we've all earned our "educations" in this business) as well as a possible learning opportunity for other agents reading the thread.
It's akin to me bringing a buyer to see a FSBO without working out compensation in advance, and then being upset that they didn't want to pay me.
You are responsible for your own situation. Does it suck? absolutely - can you learn from it and do things differently next time to protect your livelihood? Hopefully.
But accept the fact that you made a mistake and own it...because until you do, you can't learn from it.
I make mistakes too, and it sucks when it happens. I was working out a deal about a year ago between an unlisted seller (who had expired several months prior) and one of my buyers. In going back and forth I revised my Seller's Net Sheet several times in the span of 10 minutes...
Because I was rushing, I screwed up my numbers and gave the seller the wrong info (and they agreed to the deal based on my incorrect numbers). I realized my mistake 2 minutes after I got off the phone with the seller.
Could I have called them back up and said "I'm sorry, you're actually going to net THIS much, not that much" and let them decide what to do from there after a deal had already been struck? yes, I could have...but instead I owned up to it, took responsibility for my mistake and made 1.5% instead of 5% on the deal. Did it suck? Absolutely. Was it fair? That's debatable...but it was my mistake, I owned up to it, learned from it, and kept the deal together in the best interests of my customers and gained some referral business out of it.
The worst thing an agent can do is make a mistake and then convince themselves that it wasn't their fault (i.e. there's nothing for you to learn because the other agent was just being unfair) - if you learn from it, at least you'll have gained something.
The reality of the situation is that Artiste was never offered ANY compensation because she's not a member of that MLS. With no buyer-broker agreement in place with compensation from the buyer, and no MLS agreement in place with compensation from the seller....it is what it is, no?