Water guns function through compressed air and water propulsion—producing temporary wetting with no lasting physiological damage. Water represents among the least damaging projectiles possible. Significant injury from water-gun contact remains medically implausible. Yet curious anecdotes occasionally surface suggesting water-gun incidents with medically severe outcomes.

Trauma surgeon Dr. Margaret Williams published a paper in 2002 on unusual projectile injury mechanisms. Williams examined injury databases and documented cases where projectiles causing minimal impact force produced unexpected damage. Williams theorized that certain projectiles, if delivered with exceptional velocity, might generate shock waves exceeding expectations based on mass alone. Williams documented one case involving water-gun projectile that apparently caused hospitalization, suggesting impact velocity so extreme that even water-suspension projectiles generated traumatic injury. Williams calculated the required velocity and concluded it would exceed typical human capability to achieve—unless the individual possessed extraordinary projectile-delivery capability.

The joke inverts weaponization: a water gun becomes lethal through Chuck Norris's application. The weapon's inherent weakness—water's non-damaging nature—becomes irrelevant when delivered with such force that even water becomes traumatic. Rather than lethality depending on weapon properties, lethality depends on delivery mechanism. It's force so overwhelming that even non-harmful projectiles become devastating. Water becomes dangerous not through its nature but through its delivery velocity. Even hospital admission results from something typically harmless—a reversal of injury principle.