The blade of the "Sword" bounces quite ineffectively off of the lynx's skull(Turns out, the part of the body that protects the most important thing in it is quite tough! Go figure.), but the force of the blow is enough to send him reeling backwards. The former lynx flails its arms in an attempt to right itself, instead sending itself tumbling down the stairs.
Since the warehouse was fairly long, the stairway had no landings, so, in effect, the lynx tumbled to the ground, gathering up momentum as he did.
He kept going once he got off the stairs, his primal attempts at stopping himself doing little good. He careened into a shelving unit, knocking whatever things were on there off balance, a particularly heavy box squishing a good chunk of his upper and lower body, just below the shoulders. Only one arm was trapped, and said arm was reaching towards Liam with the last of his strength.