Conductivity and resistance are funny concepts, FAI, wood is a very good conductor of high voltage, and that’s what makes trees dangerous in a storm… with tensions above 50-60,000 volts, wood conducts electricity like metal, thus it attracts lightning strikes and electrifies everything around the tree that’s been hit. What they can’t cope with is intensity, a lightning strike usually haves a tension of 10-15 volts, but carries tens of thousands of amperes… so the tree conducts the high voltage static charge, and once the lighting discharges, voltage drops, the tree becomes non-conductive and all those 10,000s of amperes meet such resistance that overheat everything and are diverted through anything more conductive… human body is quite more conductive than air or a tree so people tipically get hurt by charges moving from the tree limbs to the ground through their bodies. Then if more a than a few amperes go through the heart, it’s game over.
And BTW, here in Catalonia the local TV haves a meteorologist that was struck by lightning… not the main discharge but a secondary one (the little tendrils striking around the main one); it was enough to contract all his muscles so witnesses saw him leap 2 or 3 meters away from whre he was standing and fall unconscious, but the charge moved from his right arm through the right leg and the heart wasn’t affected. It didn’t even bruise his skin so it was a very little discharge.