Since soon after publishing a new version I see crashes almost only from this device, I’m guessing it’s a Google Play new app publishing flow, where they monkey test your app.
I’m seeing crashes from Debug activities that can’t be opened in the UI, but can be accessed via a direct intent, so I’m also guessing this monkey test goes over the manifest, launches random activities directly, and plays with them.
See: http://developer.android.com/tools/help/monkey.html