EDIT

Andreas Kohlbecker wrote:

I guess that this ticket has been erroneously assigned to me.

This ticket was created 6 years ago and was part of the authorization milestone you were work on at that time.
But ofcourse we may move this now to someone else.
You are meeting anyway next week to discuss such issues.

However, someone should check if this issue is still open.

No it is the user him- or herself. So in this situation some windows might be open and functionality enabled which should not be enabled.

But as this is a very rare usecase we may think about a simple solution. E.g. we could say that chaning a persons own rights will close or refresh all windows and the user will get a warning about this before the change gets effective.
By the way it might be difficult to define if someones rights are changing, e.g. if a GrantedAutority is changing or the rights a group has. So maybe the simplest solution for now is, to generally not allow open windows when any rights are changed (except for the rights management windows).

By the way the problem could also appear that someone is changing rights while someone else on another machine works on something and this person looses rights.
However, as we still do have the server side voters it will never be possible to save something that someone has no rights for.
So, the longer I tink about this, the less I think that it is really worth thinking much about this issue.