ubiquitin,
so if My Rav says Chazir is Kosher I can eat it?
No. And that would be an example of a limited instance where the point is not true. And that rabbi would likely be out of a job by the end of the day.
If he says Johns’ cakes are kosher not knowing that they contain lard (but I know) can I eat it?
No. And that would be another example of a limited instance where the point is not true. And that rabbi also would likely be out of a job by the end of the day.
How do these extreme and thus limited examples contradict what I wrote? Or do rabbis in your community routinely tell people that pork is kosher and rule that foods are kosher without first knowing their ingredients?