Wrong about what?
You asked how to counter Lallier's objections. Lallier's "Pandora's Box" example spoke exclusively about these accomplices. Not the abortionists. That is the very example refuted by historical example.
Are you claiming this is an invalid counter-argument because it doesn't speak to the abortionists themselves? How does that have anything to do with countering Lallier, who doesn't mention them?
I responded that abortion was never illegal since murderers were never punished for their crimes.
As for the idea that history proves anything about Pandora's boxes, the government has gotten far more meddlesome in the recent past. In order to simply travel from one city to another, the government obliges me to show an ID card, waylays me and forces me to submit to groping by strangers. This in the name of defending me (something it will not allow me to do). Forty years ago, this would have been inconcievable.