@fuadhika
That's probably because most molten metal made in the backyard is straight from a crucible, which isn't very large. It's also easier to pour molten metal than to throw a large block of ice.
I don't think it would have made a difference here though. It's still really large chunks of ice with significant inertia. The point of contact between the ice and the molten rock would have had built up a lot of pressure.
There was a video about the dangers of getting water into an industrial furnace (more molten metal, less water), but it was a long video that was more or less a someone talking over a slide show of illustrations with a few video clips, so I didn't link it here.
There was also a video of small pieces of dry ice being dropped into molten metal, but it was unspectacular and didn't really cause an explosion thanks to the Leidenfrost Effect keeping the dry ice out of contact with the molten metal. For the most part, dry ice isn't even frozen water.