> I dispute the legality of doing so, when the right to jury trial is protected under the US constitution.

The right to trial by jury in civil cases with a sufficient amount in controversy is not, unlike some other rights protected against federal infringement by the Bill of Rights, incorporated against the states by the 14th Amendment; since this is a state case, there is no federal Constitutional protection.

Also, even in the federal system, the civil jury trial right doesn't give you the right to to escape liability to refusing to allow a fair jury trial to happen by withholding evidence.

…if someone doesn’t do what is required of them (participate in discovery), what would you have done?

Selective participation in discovery is not sufficient and if it hadn't been clear that he had failed to produce all responsive materials when required before the phone oops during the damages phase (which it very much was, for other reasons), that error kind of sealed the deal on that.

Problem being he actually had them, as evidenced by that data being accidentally given to the plaintiff's lawyer by the defendant's lawyer.

Hard to argue it was "impossible" for him to do something that his legal team actually did.