You're suggesting that the worker didn't realize that this wasn't proper procedure. Anyone with even the most basic level of common sense would realize that this is a problem. In what facility are you instructed to mop the floor and then turn around and use the same mop to clean a table? No place I can think of.Then the solution is to prevent the employee from working at Disney? Okay, but how does that prevent future incidents from happening? I don't think the third-party vendor can say, "Worker A got fired for not following proper sanitation and safety instructions." That would be a privacy violation, right? So do the other employees of this vendor even know that they shouldn't do what Worker A did or even that this incident happened? The story doesn't even have a cursory statement, that Disney has instructed their third party vendor "to instruct employees to follow proper sanitation and safety procedures."
I find it dubious that the worker can claim ignorance. This is basic cleaning. This was would've been laziness, aggression, or corner cutting. This cannot be a systematic training problem. I have sympathy to a point, but this is clearly not the employee's industry. I see WDW Cast Members and I'd assume contractors do an excellent job everyday of my trips. This is the exception not the standard.