The bit about the rather bizarre handling of the injured homeowner doesn’t make any sense. So much that I wonder if that part of the story is actually true, or maybe there was something different going on. Put him on the hood and drove down the road? I’m just not buying it...
I agree that the key mistake here was not passing along the essential tidbit of information to the cop making entry— that the homeowner already had the perp and was holding him at gunpoint. That cop really needed to know that. Could he have handled to situation differently anyway? Maybe, but those decisions are made in nanoseconds and we don’t really know enough to say.
The only thing that might make sense is if the situation was still deemed dangerous (there's an armed intruder who is not accounted for in this particular story and shouldn't be forgotten!) and they needed to get him clear of the situation because paramedics won't go in a hot scene like that.
Even with what appears to be lots of mistakes made, I really hate to see mistakes like this end up in lawsuits for what is inevitably, millions in taxpayer money. How millions of dollars fixes what happened to these people still needs to be explained to me before I'd award damages.