Exposure Time vs Shutter Speed

This is a followup to discussion on incorrect Shutter Speed being reported. Yes, I'm a bit of "dog with a bone" on this 😉

Further research on the EXIFTOOL COMPOSITE: SHUTTER SPEED shows it's dervied from 3 different other tags including EXPOSURE TIME.

There seem to be differences between what Shutter Speed and Exposure Time means and recored. Exposure is in  seconds and Shutter is in some other unit which can be converted to seconds. There is also consideration for step-less shutter speed which I found a reference to and am not familiar with.

So, from examing a  sample CR3 (OP used CR3)  file, here are the related tags reported from EXIFTOOL

[EXIF] Shutter Speed Value : 1/49
[Composite] Shutter Speed : 1/50
[MakerNotes] Target Exposure Time : 1/51
[EXIF] Exposure Time : 1/50

In LrC, the EXIF reference is to EXPOSURE in time and aperature which seems to imply it's using the Exposure Time. When I load the sample CR3 into LrC 12.0.1 it shows under EXIF Exposure 1/50. It shows 1/50 under the Histogram.