If you find a case where forceful pushback is sticky, it's either because the primary answer is overwhelmingly present in the training set compared to the next best option or because there are conversations in the training that followed similar stickiness, esp. if the structure of the pushback itself is similar to what is found in those conversations.
I'll put it another way - behavior like this is extremely rare in my experience. I'm just trying to explain if one encounters it why it's likely happening.
If you find a case where forceful pushback is sticky, it's either because the primary answer is overwhelmingly present in the training set compared to the next best option or because there are conversations in the training that followed similar stickiness, esp. if the structure of the pushback itself is similar to what is found in those conversations.