Why would a sane moderator delete an answer of a question without providing constructive feedback?

Question

Yesterda, I wrote an answer under the following question: Screen Resolution Problem with Ubuntu 14.04 and VirtualBox, however my answer was meant for VMware. I just thought of dropping the answer under that question, assuming someone with similar problem in VMware will come by eventually (same as I did).

Then, Sylvain Pineau very reasonably suggested that I should ask a question and answer the same on my own. I couldn't do it yesterday as I was extremely busy at the time, but I did it today: Screen Resolution Problem with Ubuntu 14.04 and VMware

Shortly after, I noticed that my answer was deleted by a moderator (i.e. Mitch).

1. What's the point?
2. Why did he do that? I had already provided an explanation about what was going on.
3. How about writing a comment there, providing an explanation about why someone undertakes that "radical" act?
4. Is that moderator-bullying?

Answer 1

The new answer (on the new question) was flagged as a duplicate of the old one. This is done automatically by the system and when it happens, at a glance it can look like a user is pepper-spraying the site with the same content. It really hates duplicate content.

What we do when we handle flags can sometimes come down to muscle memory. I'll be the first to admit I make mistakes but almost everything we can break can be reversed. In cases where you suspect we've gone off the deep end, flagging the post for undeletion or posting here is usually a good way to get our collective attention.

In this case, it looks like an unfortunate case of a bad-looking auto-flag and a mod making a mistake. Try not to take it too personally.