I think Steve Lemay is a good guy. I kind of fought with him when I was an engineer, he was a young, new designer (at Apple). But I always respected his point of view—even when we argued.

When Jobs came back to Apple in the latter 1990's "Design" slowly came to have an outsized role. I was one half of the engineering team that owned Preview (the application) when Steve Lemay became a seemingly regular presence in the hallway. As the new "Aqua" UI elements arrived in the OS like the "drawer" and toolbar, Steve and his boss (forgetting his name right now—Greg Somebody?) were often making calls about our UI implementation.

The bigger argument I remember with Steve revolved around the drawer UI element. With regard to PDF's, (the half of Preview that I worked on, another engineer handled images), the drawer was to display thumbnails for each page. If the PDF had a TOC (table of contents) the drawer is where we would display that as well.

So when you opened a PDF in Preview, the PDF content of course would appear in the large window—thumbnails, TOC (later search) would be relegated to a vertical strip of drawer real estate alongside the window—the user could open/close the drawer if they liked to focus perhaps on the content.

Steve Lemay insisted the drawer live on the right side of the window [1]. This was inexplicable to me. I saw the layout of Preview as hierarchical: the left side of the content driving the right side. You click a thumbnail on the left (in the drawer) the window content on the right changes to reflect the thumbnail clicked on.

Steve said, no, drawer on the right.

"Why? Why the hell would we do that?"

Steve was quick: "The Preview app is about the content. The content is king."

I admit that I still disagreed with him after the exchange, but I had a new respect for him as a designer because he was able to articulate a rationale for his decision. I suppose I was prejudiced to expect hand-waving from designers.

(Coda: some years later after I had left the Preview team, an engineer still on the app let me know that the thumbnails, etc, were at last moving to the left side of the app. The "drawer" as as a UI element had by this time gone away: resizable split-views were the replacement.)

(Addendum: Steve also invented the early Safari URL text field that also doubled as a progress bar. Instant hate from me when I saw it: it was as if the text of the URL you entered was being selected as the page loaded. So I'm old-school and Steve had some new ideas…)

[1] Localization was such that in countries where right-to-left was dominant, the drawer would of course follow suit.