^^ I work at a restaurant, and I highly doubt any of our servers would get fired for spilling a drink on someone once, unless it like ended up dumped over their head and it caused a big scene or something. Then again we're chiller than most places.
I was at this Mexican birthday party once and my friends restaurant and so me and a few friends were serving some soup to the guests. It was filled really full in the bowls and I handed one bowl to them and it spilled. Apologized and went for the 2nd bowl. Spilled. Embarrassing.