Flume measures continuously, and reports flow per minute.
For irritation meters... It seems that meters failing in a manner that is unusual. They do not count extra high during operation. They do not count when there is no flow. They count a correct amount for 5 to 15 minutes and then the magnets that the Flume senses seem to spin wildly, adding a huge amount of flow "usage" in under 1 minute time. Then back to normal.
These phantom bursts are not reflected in any noticeable change in water flow out the heads. And it is not unique to any irrigation zone.

Flow rate example, per minute, in GPM: 5 5 5 5 30 5 5 5 ..... 5 5 43 5 5 5 etc

Very interesting, how did you determine this?

Has anyone monitored their irrigation water usage using a Hunter Hydrawise HC Flow Meter connected to a Hydrawise irrigation controller?

Been here a long long long time now, never heard of the utility district acknowledging a "mistake", or a billing "error".