I think Lilie's explanation makes sense. Kira encountered an overly submissive dog. And as you stated, Kira took advantage of the situation.
In my neighborhood, there is a border collie, pit mix that is totally submissive to Molly. It wants to submit and roll over on it's back even when it sees us across the street. Molly has never done anything to it but tried to play a little. The owner then gets defensive and says his dog does not like dominant females, and I wonder if he's actually verbalizing his own issues.
It's nice you took Kira away, giving the puppy a break.