Some people.
@Deadpan can probably attest, there are a number of people here - me and my golden ears being one of them!!! - who have a very high ratio of being able to tell a valve amp recording from a digital one; specifically when comparing captures of the amp against the real thing, recorded at the same time as making the capture.
Obviously comparing a model or a capture of a different amp, to any valve amp at an earlier or later setting, in a different room etc, isn't comparing apples to apples.