In an assault the attacker takes possession of the hex in question if they roll more hits (after defender's defence roll) than the defender, if not the defender holds the hex. In a recent game I assaulted (with a full squad) a hex occupied by a single squad with two remaining elites (the other two having been eliminated earlier in the game). I achieved two hits eliminating the defending squad. The defender achieved three hits reducing my squad to a single infantry figure. Technically this was an unsuccessful assault (defender achieved more hits than attacker) even though I destroyed the defending squad. Under these circumstances can I still take the hex?
In this particular case it was not critical to the game but I can think of plenty of scenarios where it might have been. If this has been clarified elsewhere please provide link.