You will not get in trouble for an accident. These multiple posts/topics are generally not caused by the user. But when the site lags and the message doesn't post you may think your click didn't register when it did and click again. I have done it myself so I can relate.

I can tell you if your the last poster you can delete the last post yourself, once that is deleted if you have the next last post it will then allow you to delete that as well and so on. So you may be able to delete multiple posts on your own as well so long as no one else posts after you.

This is not an often occurrence but does happen and you will not be given a warning or be in any trouble. by report this just helps us keep the site tidy and uncluttered. Reporting it yourself would be a good idea. By reporting it, the first available Moderator would take care of deleting the extra posts.

This is a good time to remind people of that not all reports result in warnings for users.

However if a user was intentionally posting the same thing over and over would that be a cause for a warning. As that is considered spam. Please report those as well.

Yes, these are the events I am talking about.. If you are not able to delete them.
Feel free to report them or to PM a Mod to help you take care of that for you.