Aside from that, people who do so are despicable. 20 years is a light sentence. Taking money to put people in situations that could easily become deadly.
But they seem to have decided this is the least bad option. They have a duty to respond to serious phone calls about armed situations.
The main issue is the insecurity of the old telecom system where spoofing is so easy. But we're heavily invested in it as a society.
One must not result in, or be able to cause, the other.
Let's say we have to deal with the fact that they do co-exist and interact. Maybe there should be additional protection and safeguards, and if there are some (which there probably are), don't stop there until the percentage of illegitimate calls is below a certain threshold.
And maybe it is already below a certain threshold, and I'm getting all hot under the collar about an incredibly rare scenario. Maybe it's better than it was. 20-year sentences should go part-way to reducing the frequency.
I'm mostly on the side of "letting a guilty person walk free is better than imprisoning (or arresting or shooting to death or even just violating the freedoms of) an innocent person".