It takes practice to burn out the wall below the rim like that. But it's something that all Zippo using pipemen strive for. It adds another dimension to the pipe smoking experience that many have likened to the reverse calabash effect!
+1I'm certainly no expert on the subject but as a zippo user I'm having a difficult time accepting that damage was caused by the device itself. I've seen similar and even worse examples but those people in general do nothing to care for their pipes. Yeah, if you rest the insert right on the wood and puff away in a stiff breeze I'd suspect you'd get some charred wood but with normal, acceptable lighting practices, no.