The woman has only laughed at Toad and pointed out the truth: that Toad lied. But in response to this perceived transgression, Toad feels justified in insulting her and trying to put her in her place. He expects respect from lower-class people, even when he takes advantage of them and hasn’t
earned their respect. So, Toad doesn’t elicit much sympathy when the woman throws him overboard—like Mole’s experience when he ventured into the Wild Wood, this is a lesson in how all actions have consequences.