I think there are a few different elements at play with the scenario you described.
First the 'phantom' redirects, they aren't phantom - it is Google trying to show the user the most relevant search result. For example, I redirected my employers website from ab.com to a.com over two years ago now. A search for [site:ab.com] yields no results and hasn't for a very long time but if you search for [www.ab.com], Google will show the home page 'snippet' from a.com but use www.ab.com as the domain.
I suspect the logic from Google here is that you've specifically searched for a domain name and they know that ab.com was redirected to a.com and showing the user ab.com is more relevant and doesn't harm anyone since it actually does redirect to the same website. Imagine the scenario where your business name has changed completely & a user searches for your old domain name - the behaviour you and I have describe is going to be a far superior search result to show the user than the new domain (completely unrelated to the old name) that the user doesn't recognise as the old domain name or business in anyway.
Next the redirect is working as you would expect it to and it isn't going to be causing you duplicate content penalties. If you could access all of the URLs/content from your Las Vegas website but by using your pc ap dot com domain, then you'd have duplicate content issues.
Google have said in the past that they have problems when you 301 redirect some of a website and they get mixed signals about the content. Normally they like to see a site wide 301 redirect for every URL to a new corresponding URL. If you send back HTTP 200 responses from that domain or other sub-domains, Google have stated that they aren't always sure whether or not they should action the 301 redirect. In your instance, you're redirecting the home page of pc ap dot com but still have lots of other content indexed under that domain. For me personally, I'd just remove the 301 redirect from the home page and move on - that doesn't seem to be a relevant redirect to me and Google could well be ignoring it due to poor correlation between the content on pc ap dot com and your Las Vegas website.