It is the duty of the institution that has imposed the administrative penalty on you to prove that you have committed an administrative offence.
The specific state institution has to provide sufficient and appropriate evidence proving your liability. However, this duty does not mean that you will not have to prove the truthfulness of your arguments.
There are certain facts or legal notions that are presumed to be true unless you prove otherwise. These presumptions do not violate your rights as long as you are given the opportunity to challenge them.
example It is presumed that every person knows their professional duties and obligations or that they are familiar with their duties under the law of the country they are in.
If you have an alibi or any circumstances that show that you are not liable and they are not mentioned in the case file, the institution does not have to look for them. It is your obligation to bring them to the court’s attention and prove their truthfulness.