As a point of fact, be aware that getting velocity via EventHit will not work, at least for falls on characters. When characters hit, their Z velocity is zeroed (so they don’t slide around on landing as a true physics object would), meaning the Z velocity you get in EventHit’s execution path will always be zero (at least it has been when I’ve tried this).
The solution is to use Event Tick to set the Z velocity component to some Float Var AS LONG AS it’s above some acceptable value (like 500 or whatever). When the player hits the ground, you use this float var for damage calcs, and then Set it back to 0. This way it remains at 0 (i.e. applying no damage) until the player again gains aerial speed in excess of the damage threshhold you chose ahove.