This conclusion doesn't follow, it only makes sense if they are 100% busy all the time. I volunteered in an emergency ambulance a little bit and most of the time we waited in the waiting station.
Another way to look at it - 1/4 of the time people who needed emergency responders had to wait because they were busy looking into false alarms.
Your position makes the assumption that the rest of the emergency services infrastructure is at maximum use at all times.
The OP was talking about a place where they use volunteers, so it's not likely that they're constantly in use.
While you are correct that seconds can sometimes matter, it's not always true. Not every emergency call is life-or-death. Not every emergency call even requires a response.
Imaging a hypothetical world where every call is a true emergency, and emergency services are at 100% utilization 100% of the time is arguing just for the sake of arguing.
I live in a place where emergency services is over-taxed. But I'd rather have actual lives saved with a certain number of false alarms than have people die because someone decided that perfection is the only option.
"1/4 of the time people who needed emergency responders had to wait because they were busy looking into false alarms."
That would be even better, as that would mean 3/4 of the alarms are hits/non false-positives. I argue that even a 1/4 hit rate, i.e. 3/4 false positive rate, is a good start.