I am not a boid person, not for a couple of decades anyway. From what I know of IBD, it is exceedingly likely that this snake was infected when you got it. From your own intimate knowledge of everything that you did with this animal since you acquired it, I have no doubts as to how certain you are. Wandering a little bit off of your specific situation, and more just to get your opinion since you are now saddled with this problem, let me pose what I know and a question. Recomended quarantine is 3-6 months in much of the literature, although without bloodwork, a brief three months would seem to be tempting the devil. Other literature suggests that the time frame from exposure to manifestation can be as little as one month, or possibly up to one year. While your situation was fortunately manifested relatively quickly, and well within your quarantine protocols, thus leaving little room for doubt, do you know of any standards within the hobby or industry that might lend themselves to a time window of responsibility? ie. Your case is strong because of it only taking 71 days, and your quarantine procedures support your conclusions. But if it had been 120-150 days, your case would lose merit, although many arrows would still point back to Susan. With lab work costing around $200, is that a likely way to go with newly arrived animals where the value of the animal, and/or the collection it is going into, would justify the expense? It seems that Susan is trying to hide behind the time line, with "it was healthy when it left here", which is kind of lame in ignoring the nature of IBD. Should this go to court, besides your having to decide to take on the expense of recovering $915 (?), and her deciding to bear the cost of defending herself vs. settlement, I am sure that both the time-line and decisions to not have lab-work done sooner will be raised. Trust that I am finding no fault what-so-ever with your actions, but her attorney will certainly sing a more sour note to you. If nothing else, the heads-up to all who may have had contact with her, or need an IBD reminder, was much needed.