One concrete data point for the thread. If you are comparing against somebody else’s result, check that you are comparing the same measurement taken the same way. Most of the apparent contradictions in these threads dissolve at that step.

A narrower follow-up, since the general answer is now clear:

How would you tell the difference between that and the alternative explanation?

DoseLogDan said:

If you are comparing against somebody else’s result, check that you are comparing the same measurement taken the same way.

Adding the part of the answer the thread has not reached. The useful move here is to separate what is established from what is widely repeated. Those two sets overlap less than the confident tone of most write-ups suggests, and the second set is where nearly all the disagreement on this board comes from.

OP back with an update, since a thread like this is useless without one.

Coming back a few months on. It held. Nothing dramatic to report, which is the report.

ingrid_STO said:

The useful move here is to separate what is established from what is widely repeated.

That holds where the measurement is reliable. Where it is noisy — and a lot of what gets tracked here is noisy — the same reasoning produces confident nonsense.

That is the short version; the long version is somebody else's post.