I lol'd quite literally at 0:43 when the ground block became shattered glass. :O
But by the end of that segment I'd stopped laughing and started shuddering. This guy is evidently still quite new to Hammer to not only do this instead of using displacements, but to actually expect it to work. I admit someone just starting out would definitely not know how awful that would be (I didn't), but seriously ... don't make a tutorial unless you KNOW WHAT YOU'RE DOING, and make sure you've tested your own tut method to ensure it WORKS IN THE FIRST PLACE.
I see he even got some of those nonexistent, non-removable "plates" the carve tool spits out onto large complex carved surfaces. Nasty stuff, those.
I'd like to see that map he mentions.
But if my computer catches fire attempting to run it, I'll expect compensation.