Yes. This is a question that comes up a lot these days.
The Buddha allowed one to declare attainment of magga phala in the Mahaparinibbana Sutta.
However, he also noted that there are 4 types of people who declare such attainments:
1. Those who genuinely have them.
2. Those who think they have attained magga phala and thus unknowingly declare as having them.
3. Those who declare so because they have mental problems.
4. Those who do that for their personal benefit.
It is only those in category 4 that commit a bad kamma. If an upasampada bhikkhu does that he would have committed a parajika deed. Thus, even if he keeps on wearing a yellow robe, he would not be a bhikkhu. It would be a serious issue.
But the Buddha never officially expelled any bhikkhu due to such deeds. Even though Devadatta committed worse deeds (including an anantariya kamma), he did not expel Devdatta from the order of the bhikkhus officially.
Furthermore, the issue of “delivering wrong Dhamma” was even there at the time of the Buddha. One time he was told by Bhikkhuni Pajapati Gotami that there are bhikkhus who deliver the wrong Dhamma.
– The Buddha said people should listen to all types of Dhamma and decide which versions to reject.
It is easy to discern who is delivering the wrong Dhamma. My main assessments are:
– Labeling Anapanasati as “breath meditation.”
– Interpreting anicca as “impermanence” and anatta as “no-self.”
I have listened to the bhikkhu in question and just suffice to say that he is delivering the wrong Dhamma in some cases.
– I listen to various types of discourses just to get an idea.