If we see a post where a member has gone back and edited their post down to "...", "nevermind", "post deleted" or something similar, a moderator will generally delete it on that person's behalf. Obviously it gets a bit more complicated if the original poster does something similar to their original post, as that was the post that framed the entire discussion.
I'm reticent to completely remove the topic in question, because people spent time writing responses and it's not fair to just delete their words out of the existence when their posts were compliant with the TOS. Only the most venomous of topics might suffer such a fate.
As for the other topic in question, people wandered off-topic and were getting tetchy with each other. There seemed to be little interest in getting back on topic, presumably since most people still participating had already said and read all they wanted to on the topic. We try to proactively intervene and get discussions back off topic, but sometimes we just get to it too late.
If you wish to start a new topic to pick up on any loose ends still remaining from that closed topic feel free to do so... just keep it specific, focused, and in the most appropriate sub-forum.