That the spear crumbles on contact suggests that the robot is so electrified that ordinary (non-trophy) weapons touching it will shatter.
That the "million volts of electricity crackle above The Fantom" suggests that it missed. Normally, an attack like a lightning bolt would get a saving throw for half damage, not a save to be missed.
Which brings up the question, why doesn't The Fantom just wreck it? He's surely strong enough to. But, in this scenario, this robot doesn't belong to hoodlums; it's someone's legal property and he's trying to stop it without harming it. It certainly makes the scenario more challenging.
Now, why there's a chandelier in a science exhibit hall, is even more questionable...
The robot is using a bear hug, a maneuver possible in 2nd edition's grappling system.
Finally, when all else fails, The Fantom wrecks the robot --- though he seems to have a hard time of it! Unlucky dice rolls? Maybe this robot was hardier than usual?
If you don't want to go through the trapdoor at the end of an underground passage to find out where it goes, mark how long it is and then go try to find on a map where that passage would come out at. Warning: in higher level hideouts, expect magical teleport traps and the like!