Debate doesn’t normally work like that.
It is the rare philosopher who will reverse his position when presented with an argument that he cannot refute.
In fact, the well-prepared debater can generally win. For instance a teacher, I now realise a very brilliant teacher of mine called Mr Selby Brock used to present the flat-earth argument. This was a cleverly-designed piece of nonsense based on the premise that light does not travel in straight lines. No boy, even armed with a geography textbook, could refute him.
However truth does out. If a position is fallacious then, usually, the fallacy eventually becomes clear, though it may not be on the scale of a human life. Very few people are now Communists, for example.