If you have an electric igniter with a coil it is possible that a nearby strike induces energy that results in an overflash. You're correct that lightning travels through the ground, but it is also worth to note that the forementioned induced current will also occur in any material that can be considered conductive, in this case the copper pipe, and even if it is grounded on one end some of the energy may flow toward the ungrounded end and flash over.
Originally Posted by tyha
Laszlo Z Weress
Business is competition, and the ultimate competition is war. All is fair in love and war.