I personally think you did a good job. BUT i would have toned down the threats a little.. We are humans, and we are prone to mistakes, BUT some people only do the "right" thing when threatened. You did good, you did bad, in the end you got a snake and a good compensation. So don't feel all that bad. Maybe joke with the seller on your next deal.
haha, i might. im not trying to make excuses but this is the first time ive ever delt with anything like this, and ive definitly learned a lesson here