Use of milestones/sentries

Hello all,

I am fairly new to CMMN and therefore have a very basic question about the correct use of milestones/sentries.

In a video I watched about CMMN semantics, the tutor explained how to use milestones, however I am not sure if the explanation is correct.
I have reproduced his explanation (upper model) in the screenshot below.

According to him, in the upper model, the milestone is achieved after the stage completes. He has modeled this by connecting the exit criterion of the stage with the entry criterion of the milestone. The case file item, which is also linked to the stage’s exit criterion, should visualize that the stage’s information (e.g. Patient File) should be stored.
However, if I were to interpret the model, I would say that a transition in the case file instance terminates the stage and the termination of the stage would be the entry criterion of the milestone. In this way, it is not the completion of the stage but its termination that would achieve the milestone. Am I correct in this assumption?

In the model below I have modelled what I think it would look like if the completion of the stage should lead to the milestone being achieved. Do I need to model the case file item at all in this context?

Many thanks in advance and best regards,