After his apology, Willy would have extenuated his fault.
"You see, Rotha, you don't know my brother as well as I do, and hence you could not foresee what would have happened if we had done what you proposed." Still there was no response.

Willy's words came more slowly as he continued: "And it was wrong to suppose that whether Ralph were given up or not they would leave us in this place, but it was natural that you should think it a good thing to save this shelter." "I was thinking of your mother, Willy," said Rotha, with her eyes on the ground.
"My mother--true." Willy had not thought of this before; that Rotha's mind had been running on the possible dangers to his mother of the threatened eviction had never occurred to him until now.

He had been wrong--entirely so.

His impulse was to take the girl in his arms and confess the injustice of his reflections; but he shrank from this at the instant, and then his mind wriggled with apologies for his error.
"To spare mother the peril of being turned into the roads--that would have been something; yes, much.

Ralph himself must have chosen to do that.