> 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.