Problem

On Flow boards with lot of traffic such as news users forums -- like The Teahouse on enwiki, with lot of helpers, lot of time multiple responses are write and post at the same time.
Since the page is load, users have now way to avoid post message after an other answer. He only see that an other answer was posted after he click on the publish button, when the page is reloaded to show his new post.
On this sample, we can see that two answers was post seconds away.

Reproduce

Simply load flow topic a first time. With an other tab, add an answer on the topic. The first tab don't show the new activity, and user know the new post only after post his own answer.

Idea for solve problem

When user click on "Publish" on flow topic, load currents topics answers before send the new answer to the server. If this is different to the showed version, alert user and ask him if he want to reload/send/....