"what did you expect to happen" blames the victim.

"Police officer is as likely to engage in domestic violence as a cat is to kill a bird outside" is not a strong analogy. I think almost all young cats would kill birds outside. It's a far cry form "a far higher rate".

As a rhetorical device, it falls flat because it argues for something obvious by comparing it to something obscure. It would work better the other way - if you were on a thread talking about domestic violence and comparing it to cats killing birds.

Men commit violence at a far higher rate than women. But it's still lower than the "what did you expect" threshold.