Also, juries don't have to provide their reasoning for their decision. So it could be based on not wanting to convict a police officer, based on liking how he came across in court, based on a misunderstanding of the burden of proof, based on disliking the prosecutor, based on not wanting to be responsible for sending someone to prison...
I wouldn't take it to mean they necessarily believed he accidentally strangled her. They may have formed the view that the prosecution did not meet the legal burden of proof (or may have misunderstood what the reasonable doubt instruction meant") or any of a number of faulty reasons.
I don't know why people think jury trials are a good way of delivering justice in the way people mean here. There is no transparency and no recourse for faulty application of the law because they don't have to publish a judgment like a judge would, who could then be challenged for erring on a point of law.
It's the system and structures that need outrage, attention and change.