Every hail event is different and has to be assessed one event at a time on its own uniqueness.This particular hail event occurred at the 11th true leaf stage of the crop.Though this event did slice the leaves some and do some minimal bruising to the stalk the overall yield reduction it will cause will be minimal.Based on the Crop Insurance Societies of America hail simulation tables it would suggest expected yield losses in the 1-2% range.The above photo depicts how the new leaves V12-V19 have developed just fine since the event occurred.
The above shot shows how the lower leaves(Leaves 5- 12)
have been shredded though very little defoliation of leaf tissue has occurred.Hail injury can cause wounds that will lead to common smut infections.When lower stalks are severely bruised it can lead to increased stalk breakage near harvest.

We know a great deal about how corn will react and perform when impacted by hail at different stages of growth based on simulated research work commissioned by the Crop Insurance Agencies of America.