If you are blocked by a person on twitter and you click by mistake on a tweet of that person (fovorite or retweet), can you undo this? I have done this, but I can't see the tweet in my timeline or by my favorites. So I can't undo this. Though, if I go to the tweet of that person on his timeline, i see that I have retweeted it (or favorite it). How can I undo this?