When the editor of a paper I recently reviewed circulated the final decision letter to myself and the other reviewer, I was surprised to see that the other reviewer had apparently had access to my peer review before submitting hers. This was clear because her review explicitly referred to comments made "by the other reviewer". Note that this was definitely another peer reviewer, not the editor.
I've never been given access to another reviewer's comments before submitting my own, and I'm curious as to why an editor might choose to do this. Don't editors typically want the reviewers to be independent of one another?