Yep, you see this way to often. Of course the correct fitting with a ground lug is available. While we're at it, that cobbled together transition fitting is not compliant either.
In all the pictures what we this side of the pond would call a CPC looks as much use as a piece of wet string. OK our regulations are different to your codes but the safety aspects are the same.
1. Did it in a situation where the conductors were already run on 6” conduit and someone forgot grounding rings on a nonconductive box. External ground was cheaper.
2. In mining the fittings often corrode especially liquidtight to motors. Ground testing from load to rod is required annually. It often fails within 10 years or so. So either redo the whole thing or add an external bonding jumper.
3. Trays that are part of bonding require jumpers.
My comments in post #4 were in the context of when an external jumper is required. But I missed the fact that infinity was trying to get across was the fact that the jumper was not required in the first place and I would agree.