Orion BN/KL is an example of a poorly understood phenomenon in star-forming regions involving the close encounters of young stellar objects. The explosive structure and dynamics, the energy involved in the event, and the mass of the region suggest a contribution to the motion in the interstellar medium. We explore an analytic/numerical model that takes into account the interaction of a clump with the environment. We show that the widespread kinematic ages of Orion’s fingers—500 to 4000 yr—are a consequence of the interaction of the explosion debris with the surrounding medium. This model explains satisfactorily the age discrepancy of Orion’s fingers and infers the initial conditions together with the lifetime of the explosion.