However, the first amendment is not absolute. Defamation is still a thing in the US. The first amendment creates a higher bar than many other countries (especially for public figures, but the victims in this case aren't public figures), but it is still possible.
If I were to bring a civil suit against you because the comment above offended my sensibilities, it would be quickly thrown out of court because it is your first amendment right to say anything you like, with certain exceptions that the government recognizes as limitations of this right.
Even though this is a civil matter, it is still a judgement on government law. This is not some contract dispute where the parties are simply seeking arbitration, with no government involvement except as a "service provider" for this arbitration.
He did take actions that, by civil law, created civil liabilities. He was sued over those liabilities. He failed to participate in the civil litigation process and lost badly as a result.
Civil and criminal law are not the same thing and your insistence otherwise doesn't change the reality.