I was not the one that said it was "passive-aggressive." Check you source.
Possible reasoning: "Yanking a leash" may be aggressive to you; to me, "leash yanking" is the same as attacking someone from behind - pretty weak. If you yank a leash, you are most likely behind the victim. Plus, it's not as "outright" aggressive as you think - my 8 year old cousin does that.

