I know it's an old thread, but I'll reply just in case anyone in a similar situation finds it.
The problem described happens because the Google search result takes you to the main Wikipedia page. Wikipedia then detects that you're using a mobile device and sends you to a different page formatted for reading on a phone. If you now press the back button you are taken to the standard Wikipedia page, which again redirects you to the mobile page. It will do this forever and you'll be stuck in a loop unless you press the back button a few times rapidly. You'll then be back to the page which you were at before clicking on the wikipedia link.
The number of times you need to press back rapidly depends on the number of redirects the site you're on puts you through. Some sites need two, some far more. All this trick does is beats the page reload time so the redirection doesn't get a chance to take place.