Earlier quoted context omitted.
I noticed that too and wondered if it was by design or a bug in the implementation. I haven looked at the source though so can't answer knowledgeably.
It's a side effect of the way iOS implements scrolling--as soon as scrolling starts the web content is "frozen" and only resumes once the scroll is complete. Only way around is to imitate the native scroll using CSS and JavaScript.
But why is the item selected in the first place? It's not like it's doing the same animation as when the item is actually clicked (at which point it turns blue).