a few little points

1: The only means of establishing beyond doubt the contents of a sealed, impervious, opaque container is to unseal it and observe the contents directly. Some properties may be inferred by indirect measurements but inferences are not proven facts.

2: There may be no difference between a state of affairs proposed in a supposition based on extrapolation of observed evidence and the real world. There may be a considerable difference. The extent of the extrapolation beyond observed evidence and the size of the gap between the supposition and reality are still descriptive but of the description-attempter rather than the system the attempt to describe attempted to describe.

3: Just because you can't see any footprints it doesn't mean there's no-one there.

All of the above work both ways. Examination of available data such as output and behaviour permits entirely valid conclusions to be drawn about them without fear of presuming to draw conclusions about their reasons for being and the process by which they became. Similarly, any attempted description of the process by which a conclusion was achieved based solely on the conclusion is presumptive and liable to be inaccurate.