EyeAmEye
I know exactly what you're talking about, and I can tell you that, in the past, the very same thing happened to me...but that's an entirely different story. I know that can happen, mistaking one person for another; this reader I know in a nearby town, where I also sent my friend, made the same mistake with me years ago, talking with plenty of details-which all turned out to be amazingly correct-about a guy who, unfortunately, was not the one I was asking about, but someone I met shortly after....but this time, I don't think this is what happened here. There were too many details that matched, the background to the story, everything...and this is not the first time it's happened, not the only similar story I've heard...I don't know, sometimes I wonder if tarot, when we really get to trust it, starts playing tricks on us...some catholics I know say that that's the proof that the Devil is behind it, making us think it works, only to make fun of us....I don't believe that, of course, but hey, I'm prepared to listen to all theories by now....
And I think the devil sent the catholics to throw us off the course... (just kidding!)
Here's another angle to consider. Skeptics love to suggest that readers lead their querents. I often believe it works the other way around as well. In the give and take of a tarot reading (unless the tarot reader does not engage in any kind of feedback), I don't think there is any way in which a reader cannot be somewhat directed or influenced by the querent's feedback. That can cause a reader to "see" something in the cards that is not there. Yet another wrinkle to think about.
I know at times I have read for a querent and initially very little came to me until I started a bit of give and take. Once the querent started filling in gaps, the cards seemed to be easier to interpret. I may wish to believe that somehow the feedback opened my intuition and helped me apply the message to the situation, but it could also have been me using the information given to change the message to best suite the situation.
Since I gave a fairly abrupt answer to your initial question, I will add a little more to the mix. My initial response probably sounded overly fatalistic. I do believe life is a mix of fated and free will events. There are some things we can change and those we cannot. Tarot can answer any question you wish to receive an answer for. The accuracy of the answer not only is dependent on reader's ability to interpret the cards but also the degree in which that predicted future is variable or not. So, in essence, you can read a future that did not come to pass because perhaps that situation was heavily dependent on your own free will.
Last bit o'wisdom (or unwisdom coming from me) is that I believe tarot, or any other divination method, requires a lifetime commitment to even hope to master. I would naturally assume the overwhelming majority of readers will never reach the level needed to truly tap into the full power of it. We all can have moments of amazing lucidity, but it doesn't last. We have to understand that and question ourselves as readers and not "tarot" as a whole.