The spear's secondary attack has two distinct modes: at medium+ range, and at short range. At short ranges, beyond spear attack range but not much beyond that of a two handed weapon, the 'throw' acts exactly like a long thrust *if* you hit the target. The spear will immediately recover back into your hand, no hitting the ground.

It does take a bit of practice and you definitely do *not* want to miss.

IMO, the biggest problem with the spear is that it has a separate skill from the Atgeir - the spear skill should be polearm.