Skirting a Clam Chowder Disaster

I come into the office after grabbing some food for my lunchbreak. I open up a cupboard to grab a plate.
A clam chowder can half full is sitting in the cupboard. I stare at it...in amazement. A coworker sees me and says, "Oh that is so and so's and they were going to come back and get it."
Me - "When was that?"
Coworker - "About an hour ago."

Now the smell is already leaking out of the cabinet and I notice that spillage from someone pouring some of the chowder out has leaked down the side onto the cupboard so I toss and go to find the employee.
They are at their desk eating chips.
Me - "Was that your can of clam chowder?"
Employee - "Oh ya. I will eat it on my break."
Me - "That's 2 hours from now. It was sitting in the cupboard."
Employee - "Ya I didn't want to have it get smells from the other foods in the fridge. I didn't want it all right at lunchtime."
Me - "Right but its clam chowder. The stuff stinks, and I am not sure but it is probably best not to let it just sit out in a cupboard."
Employee - "Oh ya I see. Go ahead and toss it."
Me - "First you can get off your ass and do it normally. But this time I already threw it away."
Employee, now angry - "You threw it away?"
Me - "Yes. It's fucking clam chowder sitting out for over an hour."
Employee - "I could have still eaten it..."
Me - "Could is the operative word. Cause its thrown away now. Use the fridge from now on."
Employee, who is now hurt at my tone - "I don't see what the big issue is."
Me - "Seafood left out in a warm environment, in a cupboard with clean plates doesn't strike you as odd?"
Employee - "No I do it at home all the time."
Me - "This is not your home."