User can delete other posts without DELETE_OTHERS_POSTS permission being granted

1. User1 and User2 have DELETE_POSTS permission, but do not have DELETE_OTHERS_POSTS
2. User1 leaves an answer, the page is left open, do not close it.
3. Open another page and log out there
4. Log in with User2, open previous tab where you still have Delete button available.
5. Press the button and delete the post.

AR: user will be able to delete post even though she has no permissions for that
ER: user is getting Permissions Denied error after sending the updates