Here is what I have observed in regards to the garrison altar and the orb. Please correct anything I have wrong or add to this if you have more info. I didn't see another thread on this so forgive me if there is one and this is a duplicate.
The north Quaggan weather node, when it is friendly to the enemy, can and will damage the garrison altar over time. You can tell if the Quaggan are friendly with an enemy team by the color of the two pikes that designate the weather node. It's a good idea to keep an eye on that northern node and destroy it if it is active. If no enemy are there, a strong single person or a couple people can destroy the node fairly easily. It doesn't take a lot of people or a zerg to destroy it unless the enemy has a team protecting it. I have soloed it on my 80 engineer many times and I know Kraas can take it out in a few seconds.
Secondly, it's a good idea to monitor the health of the altar. If the altar is getting very low on health, have a 2-man team hang around and wait for it to be destroyed. When the altar is destroyed, have one person pick up the orb and have the other person stand by the broken altar and spam "F". You should see the altar "heal". Have the person spamming "F" do this until the altar is fully repaired. This is key. It seems to me that a lot of people think once it is destroyed the altar is just gone. That is not the case. After the altar is full health, the other person holding the orb can place the orb back on the altar and all is well. From what I have observed, you cannot heal the altar while the orb is in place on it. I also don't think you can pick the orb off the altar temporarily while another fixes it. Again, this is just my observation.
What does this all mean? I think it's just a mechanism to be able to have the orb reset back to the northernmost altar to make it fair game for the invaders to attack if the team owning the orb does not take care of it. And this applies to the altars at the east and west keeps as well. There is an east and a west weather node in the lake and if those are active it will hit the altars on their respective sides the same as the north node will hit the garrison altar.
So the enemies in SoR borderlands were really good at keeping that northern weather node active. In a scenario where our defenders don't understand the weather node/altar mechanics, it could happen that the altar is destroyed, the orb sits there on the ground for 15 minutes, then the orb resets to the north altar and the enemy has a team waiting on it. Bang, the enemy owns the orb assuming they own a keep and make it back to their altar. Now if people do not understand the mechanics they just see a) all the garrison walls and gates are up and b) the enemy now "somehow" has the orb. Then here come the hysterical claims of hacks, etc.
Now there are hacks out there apparently but at times it's just a case of not understanding mechanics, not hacks.
Things I don't know: if the node is our color, does it hurt us? I don't know.