My aim wasn't to offend anyone. Well unless you're a cop that commits domestic violence. They should probably be offended.
It was a tactless analogy, but a strong analogy nonetheless.
"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.