I had a very bad experience when downvoting an answer: I left in the comment the motivation of the downvote, and after that, the user clarified a little bit the answer I removed the downvote but the user seemed to have taken it very personally. I was very sorry that I had upset somebody but I thought that I provided my motivations and I wrote the observations kindly. Unfortunately, the user deleted some of its comment so the conversation is not complete.
Then I saw a strange trend in my account, and it seems that the user downvoted all my answers as revenge for my act:
It really left me with a bad experience. What was my mistake? Should I have avoided to downvote? Or to leave a comment with an explanation?