It is an infinitival perfect construction. It can easily be paraphrased with a tensed version instead, where the choice between present or past depends on the context. In this particular case, we can only do it in the past because the main clause is in the past tense. If the main clause were in the present tense, we would have to choose the present perfect.
Han kjørte videre etter at han hadde truffet en syklist. - Past perfect.
Han kjører videre etter han har truffet en syklist. - Present perfect.
Han kjørte videre etter at han hadde truffet en syklist. - Past perfect.
Han kjører videre etter han har truffet en syklist. - Present perfect.
