Its unfortunate you're being marked down by people who don't realize that memorable events create recallable memories.
It's easier to remember the first time you do/experience something. The situation is novel and unique, which creates stronger mental connections that allow for subsequent recall.
If Dorian was the 15th guy to buy something with Bitcoins from the retailer, that would definitely be suspicious. But the first guy to buy something from you with Bitcoin? That's a memorable event. That doesn't mean it happened, but it does mean there's a good chance it actually happened.
Eyewitness accounts are known to be incredibly unreliable and full of bias. I saw a show once when they staged a bank robbery or something like that. Later they showed interviews with witnesses who got every single detail about the suspect wrong (ethnicity, clothes, etc) and details about the robbery wrong. They were asked questions like "did he have a gun?" and they mostly answered "yes" even though he didn't. It was nuts.
In one of her experiments, Loftus demonstrates that false verbal Information can integrate with original memory. Participants were presented with either truthful information or misleading information, and overall it showed that even the false information verbally presented became part of the memory after the participant was asked to recall details. This happens because of one of two reasons. First, it can alter the memory, incorporating the misinformation in with the actual, true memory. Second, the original memory and new information may both reside in memory in turn creating two conflicting ideas that compete in recall.[13]
It's easier to remember the first time you do/experience something. The situation is novel and unique, which creates stronger mental connections that allow for subsequent recall.
If Dorian was the 15th guy to buy something with Bitcoins from the retailer, that would definitely be suspicious. But the first guy to buy something from you with Bitcoin? That's a memorable event. That doesn't mean it happened, but it does mean there's a good chance it actually happened.