I do webdesign and programming professionally. Here's my take on the situation:
There is no doubt in my mind that those "imaginative" sites required more creativity, time, and thinking to create than some programs. I've done my share of complicated layouts and I know how it is. So, when I am informally communicating, I occasionally refer to it as "coding." It is convenient and to the point. "Typing" is not an accurate term when you're figuring out how many colspan to use, or if you need to embed a table within a table. It's not quite "design" to me, either, since that, to me, refers to what is actually seen, not the underlying structure of the webpage.
If someone is typing HTML and casually says they are coding, I let it go. Getting on their case at this point would be a game of semantics, and I think, also elitist.
On a side note, you can do a pseudo-conditional jump in plain HTML (i think this tag has been here since HTML 3.0) based on timing. Put
<meta http-equiv="refresh" content="timeout;URL">
in the head and a link (<a href="...) in the body. Without human intervention, the client would go to the specified URL. With human intervention, the client would go to the URL referenced in the link if the user clicks on the link. For example, you could create a page that said "you are in a cell. you can escape through a hole in the wall or through the unlocked gate." If no choice is made within a certain amount of time, the client would fetch a page that said "You fester and die in the cell." It's kind of a kludge, but would that be "coding"?
This reminds me so much of discussions about the difference between cybertext and hypertext, and how they sometimes overlap. Maybe that's the case here -- there is no hard and set line.