Ask them what you should have done?
Tell them to use MS-Editor and the dos console?
To do a job you need the right tools, and when it comes to tools only the best will do.
Among them are imho Eclipse, jEdit and NetBeans.
You thought Eclipse is the best and thus you gave them the tool you thought was best.
If someone thinks Eclipse sucks... well then they should stay away from anything more complicated then a stick!
If you want to really rub it in, tell them you would gladly run through it with them step by step to make sure he gets it.