Having a box and dumping gear is a very common tactic. At that point if the defenders wanted to do something about it they could have charged out and broke the box. The enemy has no obligation to retreat as long as they are doing something productive.... just because it is not fun or helpful to their enemy is not an issue.
Actually, it's against the rules. For your enjoyment:
http://forum.melee.org/strategus-general-discussion/strategus-rules/Excerpt for the lazy (like you):
Battle/ siege
1) Prolonging a battle
1.1) End battle, common sense rule. Feel free to troll around when the battle is over, but don't extend it too long, crpg no delaying rules applies here.
1.2) If the attacker is out of siege equipment, and no longer has any way of getting into the castle or town, he has to retreat ("getting into the castle" means getting in the defender spawn zone. If defenders are in a place that cannot be reached from their spawns without siege equipment, they will have to come down).
2) Spawnraping
2.1) Spawnraping the enemy is allowed. It's your teams responsibility to defend your flags, if you lose controle over an area you might get spawnkilled.
Note: It doesn't say anything about being 'productive.' 1) If you have a ladder, and choose not to use it, and choose to simply sit back and do nothing, then the delaying rules apply. If you have no means of getting into the castle, then you must retreat.
These are rules. Black and white, clear cut situations. Seriously, I'm fighting this one on principle. I don't really care either way, but remember, what you do (and get away with) can/will be done to you in the future, and when the role is reversed, that's when you'll care.
