The following is respectfully quoted from “Perfect Conduct” with commentary by Dudjom Rinpoche:
4.b.3(b.2) Contradicting the Buddha’s words:
The second concerns the utterance of the sugatas, who reveal what to accept and what to reject. This includes the lama’s speech. To knowingly contradict it by engaging in unwholesome conduct is the second downfall.
The words of the sugatas clearly reveal the path of what to accept and what to reject in accordance with the advice given by one’s lama. The Tripitaka and the four tantras all qualify as the sugata’s utterance. Ignoring these teachings, acting in opposition to the three trainings (prātimoksa, bodhisattva, and Vajrayana), and displaying such conduct in front of others transgresses the Buddha’s speech. This downfall is second in weight to directly disrespecting the vajra master.