Earlier quoted context omitted.
I'm a bit confused... I just typed "sketch" in Safari on my phone. The first suggested result was indeed skechers.com. But then I hit enter (so the total keystrokes were "s k e t c h return") and it did a search in my default search engine for "sketch". Which is what I expected. so what am I doing that you're not?
I can confirm the "s k e t c h return" -> skechers behavior. "s k e t c h SPACE return" got me the google search results.
I can get the Safari team to look at this, but I can't reproduce either behavior myself. Any other examples of bogus/unexpected autocomplete also welcome.