The officer seems to have been more indifferent than downright malicious in this situation. Like G30USMC said, I've seen the old "I havta pee" routine on Cops more than once.
It's unfortunate that your daughter couldn't make it to the bathroom and that your wife is in the midst of a stressful time in her life, these are all parts of life and we just have to move on. Try to be the anchor for your wife & family at the time, letting your wife vent about the situation is priceless, now help her to leave it behind, she has other important matters to attend to.
Just one man's opinion, but you did ask.
Our condolences to you and yours during this time, I pray for peace for you all.
"Your fear is 100% dependent on you for it's survival." - Steve Maraboli, Life, the Truth, and Being Free