You might note that it is simple to avoid that problem and eliminate some others as well.
Just swap the paddles from hand to hand each time that you zap.
It is a simple solution to the problem that you mentioned and we have been recommending it to our customers for a couple of years.
It also helps eliminate at least one other problem. One hand holds the return or neutral electrode. Any parasites hiding near this point are much less likely to be killed by the zapper. Swapping paddles from one hand to the other reduces this problem.