Does ばかり (meaning 'just happened') have to be a voluntary action (like たところ?) Is the same as in the sense that the action must be voluntary? e.g. Winter just ended, could you use

**_Both_** and can be used to describe the endings of either voluntary or involuntary actions.

It is perfectly grammatical and natural-sounding to say all of the following:

{}{}/{}{} "Winter has just ended at long last. We couldn't go bathing in the sea yet."

{}{}{}{}/{} "I've just finished eating dinner. I am stuffed."