For fully automatic schedules (Flex Daily) this easily happens, although not frequently.
One hour before scheduled start time the Iro2 checks the forecast. If forecasted rain is not enough to keep the zone above the dry threshold then the schedule will be ‘scheduled’ to start the next hour.
Meanwhile, the forecast can end up being wrong such that a lot more rain comes than expected. Enough so that with hindsight the schedule run wasn’t needed. It happens.