How to ruin a lunch with lemonade

Not because of taste. I'm sure the restaurant I ate lunch today had the best intentions with how they served my lemonade; it came with a lemon on the edge and two (tiny) black straws, as opposed to my water, which came with only one black straw. It was hot today, so I finished off my lemonade very quickly, but in order to do so, I had to remove one of the straws and the lemon (they were in the way). Apparently by removing the lemon and second straw, my empty glass of ice became an empty water glass because the bussboy filled it up with water instead of lemonade every time he came by.

What loss of productivity would the restaurant have suffered if the bussboy had stopped and asked me if I was having water before he poured? I did leave the second straw and lemon right next to the empty glass, so if that was the magic formula, the bussboy might have taken a second to notice those items which normal denote lemonade as having been in my glass at some point.

Now, I am sure when someone at the restaurant came up with the plan of a system of cues for different kinds of drinks, they may not have anticipated me deconstructing their system or maybe they assumed that the bussboy would still ask before pouring.

The biggest problem with their system may have been that I only saw the waiter when I ordered -- another waiter actually wound up bringing me my check. Perhaps the waiter would have noticed that I had an incorrect beverage and rectified the situation, while at the same time explaining the system to me.

So what's the lesson? Here goes:
If the majority of your customers are going to have the most direct interaction with the "low man on the totem pole," then the lowest person should be the best trained in customer service.