There does seem to be actual policy-related reasons why officers might not respond:

Even when agencies do instruct officers to give first aid, as many police departments in large cities do, officers often lack the training or equipment to handle gunshot wounds.

“It’s typically geared toward, you come across an auto accident, or someone is having a heart attack or choking,” said William Johnson, executive director of the National Association of Police Organizations, a coalition of police officer unions. “If there’s a gunshot wound, the typical training is for the officer to call for medical help.”

Some agencies have increased medical training in recent years, and others, like the police departments in Cleveland and Los Angeles, have equipped officers with trauma kits that contain items such as tourniquets, bandages and sterile gloves.

“In my 20 years in the Newark Police Department, not once did we ever have the equipment to deal with something as serious as a gunshot,” said Jon Shane, an assistant professor at John Jay College of Criminal Justice in New York City.

Perhaps the reporter should question why other departments don’t follow the examples of Cleveland and Los Angeles. But these seem like pretty substantive policy-level critiques that go a certain way to explain why first aid isn’t rendered.

The statement about distance between officers and the communities they serve comes from one of the critics you cite and not the apologists. Maybe the speaker could have just said it was racism, but it doesn’t sound like she is trying to be “polite.”

And if you go further in the article, there’s mention of other reasons why officers might not render first aid in those situations:

Yet others say that what looks like disregard for life may just reflect human nature. A person who has just shot someone is flooded with adrenaline, sometimes traumatized, and often not thinking clearly.

What seems like callousness could also be a product of training. Officers are taught, above all, to secure the scene when force is used — to make sure the person, a suspect, is unarmed and that there is no one else around who can pose a threat. In some places, department policy calls for handcuffing the shooting victim.

“There’s a difference between officers just standing around while somebody is bleeding to death, and being sure you can safely approach the individual who’s been shot,” Mr. Bueermann, the Police Foundation president, said.

Now, there we do see another vague authority attribution (“yet others say….”) and we get another appeal to “policy,” but this time a policy that exists and tells people what to do, not a policy that doesn’t exist yet. At the same time, those reasons seem at least arguable.

Some of your other criticisms are spot on. A lot of that information is buried toward the end. And as I’ve admitted, the “experts say” and “others say” trope seems to be used irresponsibly. This article could have probably been stronger. And it does seem to exhibit an overreliance on the police-side of the story. But it’s not quite as weak as it might seem on first glance.