I thought he was ramming home his point that his opponents are secretly deontologists there
I think the point was that his opponents are openly deontologists, making openly deontological arguments for their openly deontological position, and therefor they are rightly confused and not moved by Yvain’s refutation of a shoehorning of their position into a consequentialist argument when they never made any such argument, which Yvain now understands and therefor he doesn’t do that anymore.
Arguing that the consequentialist approach is better than the deontological approach is different than skipping that step and going straight to refuting your own consequentialist argument for the position others were arguing on deontological grounds. Saying they should do some expected utility calculations is different than saying the expected utility calculations the haven’t done are wrong.