I've been trying to remember the situation with Leon when Captain Lee fired him. I think that Captain Lee expected him to finish out the charter, as well, so maybe, just maybe, Sandy isn't that far off the mark. And, Captain Lee didn't technically fire Leon "on the spot". He told Leon that the charter would be his last, and then Leon said "well, I think I'll just leave right now." I think I remember at the time, that many posters, including myself, were outraged that he would not finish out that particular charter as expected.
Although, Captain Lee did not fire Leon in front of practically the entire crew as Sandy did to Kiko, and I think that they only had one dinner and breakfast for the guests. With Kiko, I think it was two dinners and a breakfast.
I really hate to admit this, there isn't much difference between the two scenarios, except for the reason for the firing. One chef nearly burned down the boat because his lack of properly cleaning the galley caused an oven fire and the other chef just sent out too much fried food and bad looking nachos for one of four dinners of a charter, which the clients may not have raved about but also did not overly complain about, either. One other difference is that Leon was a raging, angry, no talent, mysoginistic asshole and Kiko is an extremely likable, good looking, upbeat and semi-talented nice guy.
While I am completely on Kiko's side and had tears in my eyes throughout most of this episode, this is just a little food for thought.