Who is a party involved in an accident?

You answered correctly. In German traffic law, a party involved in an accident is anyone whose actions may have contributed to the accident or who actually caused it—this includes drivers, cyclists, or pedestrians whose conduct was a factor. A witness, however, is not considered a party involved in the accident—they only observed what happened and didn’t contribute to the incident. Remember this distinction: only those whose conduct or fault played a role are considered participants according to traffic regulations.