I can't get this quote out of my head. ^^;

"But then I'll go to Hell for stealing."
"Baldrick, believe me. Eternity in the company of Beelzebub, and all his Hellish instruments of death, will be a picnic compared to five minutes with me... and this pencil."

I get it now!!

Because they would have had to record the shot backwards, so the dog would look as if it's being pushed instead of pulled when played properly. And thus the leash could be attatched to the neck of the dog, without it being some kind of superleash.

Me gets it. ^__^