No one have been given a probation for plagiarism so far, nor does anyone deserve it. If you can't follow the rules of a place, you don't deserve to be there, and you will probably get kicked out if you are caught by the law makers for breaking the rules that you were supposed to understand and follow.
There is a big difference between a mistake and a crime, and plagiarism is considered to be a crime. One may be granted forgiveness for a mistake, but never for a crime.