I just saw this headline on the internet: "Galaxy Nexus: Android Ice Cream Sandwich guinea pig".
My knowledge in English tells me the construction is wrong because of a missing apostrophe after "sandwich", but in the website I saw it nobody seemed to point this out.
I saw a print screen of it on Reddit, by the way, but since it was a headline of an article, I assume any mistakes would have been pointed out.
Is this sentence construction wrong?