"I'm all ears" said in a positive tone can be "Absolutely I agree, I'd love to hear your ideas".
"I'm all ears" in a negative tone is more like "Prove it. I don't think you have any ideas to this unsolvable problem."
All a matter of interpretation, I suppose :) (and fwiw I don't know whether the author meant it in a positive or negative tone)
If someone is rude to someone who's mistaken that could help them unlearn something, but more likely they will become more entrenched because of consistency principle.
Cialdini talks a lot about consistency principle in his book the "Influence: The Psychology of Persuasion"
https://www.amazon.com/Influence-Psychology-Persuasion-Rober...
It's not always natural and of course we all fail at it from time to time, but justifying poor behaviour because someone else started it just isn't cool.