When you set a vehicle to be the extraction target, then it blows up when extracted. This suggests that the extraction objectives (the blocks) are blowing up, but that they blow up by animating as if they are ionizing into a vapor. This would explain why shooting them results in the same ionizing behavior. I have tried blocks, they do nothing. I have not tried explosives. Someone may want to try to make a mini game out of this trick by having some people in banshees and the other people try to arm the extraction zones before the banshees stop them.