My dad was stuck by lightning (TWICE!)

You can't have high voltage and low current. You can have a high static voltage, but as soon as the discharge starts to happen the voltage drops, due to mainly a high internal resistance (the charges can't get to the surface and jump the gap fast enough). So you have a low (or lower, it still needs to be fairly high to discharge at all) voltage low current discharge that happens relatively slowly. Your demo actually shows this quite well, the discharge is much faster (higher current) when it is metal to metal than when you put a piece of meat in between, which has a much higher resistance.
There is also a very limited amount of total charge released, so the amount of energy actually being transferred is very low.