One honcho at todays press briefing mentioned that the retractor reels activated even though the harpoon darts didn’t fire. Maybe he was trying to clarify what you heard him say yesterday? Keep in mind that they theorize that a comet is made of ice, so I am sure the harpoon anchors were designed to embed in ice. Suppose a comet is rock. I think that if you tried to fire ice-harpoons into solid rock you might just knock yourself a half-mile or so away from the comet. Should we be buying this half-mile high bounce explanation (from a meter per second speed on impact of an object weighing a gram)?
The mass of the lander is given as 100 kg. At 10-4 g that is 10 gram-mass units of "weight" on earth. In a constant g-field of this strength, the height of a 1 m/sec launch is 1/2 g t2 = 1/2 v2 / g = 500 meters . It should have rebounded less than this, as the landing was "damped", but I think the 1 km value was supposed to be a lateral distance, so it's of the right order.