Even if you reflect an assembly, its not really the code the programmer wrote. It’s just a best guess at the originating code based upon the IL assembly. This holds doubly true if the project file has the “Optimize Code” option checked.
A nifty feature is the ability to view disassembled code as pure IL, C#, VB.NET, and more recently F#. Its really nice if your trying to learn F# or implement F# technique in C#.