Twitter tries to show the original author's thread-tweets uninterrupted. However, sometimes the thread gets broken -- generally in very long threads -- and it s

Twitter tries to show the original author's thread-tweets uninterrupted. However, sometimes the thread gets broken -- generally in very long threads -- and it starts showing replies from other users rather than the next tweet in the thread. It's not happening here, so I'd assume that the person you're responding to has just had a few bad experiences trying to read threads like that in the past. (It happens with the twitter web client and app, so I'd assume it's something to do with how they build the thread server-side, rather than being something where it's meaningful to ask about the client being used.)