Even of the time length there, it is a fact (is?) that there is no observable acceleration before the object travels its speed? Man, how big force would that be, and it seems to not be emited by matter adjusting during collapse, too few energy to overcame donated energy of contact, right?
There is an acceleration, it's just extremely fast because the objects only touch for a very small amount of time and a large kinetic energy transfer is carried out over that time interval. The acceleration can be huge (like on the order of several thousand g's) but it isn't infinite.