Once you drain one side, the majority of the oil is gone. You do the other side to get the small amount that pools at the bottom on the other side, at least this is how it was on my CK. That is why it's much slower on the other side or may seem like it's plugged.
He is referring to posts in a previous thread although I don't remember which one, but that would clarify things for those who haven't read it. If memory serves, the lack of response from the dealer relates to an even earlier thread in which he had issues with tires being installed incorrectly and having to go to war with the dealer (please correct me if I'm getting my stories mixed up). I think I said then and I'll say it again, forget that dealer exists and move on to create a positive relationship with another dealer, no matter how far away that is. Yes it sucks having to go further, it'll even cost you more in gas to do it, but since there's bad blood with your current dealer and he sound incompetent anyway, it will likely end up saving you money getting it done right somewhere else, and certainly a lot of grief.