You don't even need to call him to the stand, it's not some gotcha, he writes it all over the complaint itself. "AGI poses a grave threat to humanity — perhaps the greatest existential threat we face today." I highly doubt a court is going to opine about open vs closed being safer, though. The founding agreement is pretty clear that the intention was to make it open for the purpose of safety. Courts rule on if a contract was breached, not whether breaching it was a philosophy good thing.