I checked with curl and no matter the user agent it will answer with a 302 to google maps, I don't know how it works that others say it will redirect them to the Apple Maps App.
Yeah what it's showing is that on iOS/Safari (user agent) it returns a maps:// protocol address. This makes sense of all the reports here - it's trying to direct you to whatever maps app you've selected. Redirecting to google maps makes sense if the server doesn't think the maps:// result will do that.
