As mentioned above, I'm still not sure how they release the guy if he was injured. They should have had to negotiate a medical settlement with him before they released him. Unless he got hurt after he was released which seems unlikely.
Going into the wayback machine here ... Drew Brees failed his physical with Miami in 2006 before the Saints signed him.
1) Did San Diego release Brees with an injury designation?
2) Brees presumably passed the Saints' physical. Teams obviously have different standards, correct?
I ask the second question because is it possible that Nwangwu wasn't really considered injured by the Vikings? Or maybe: any chance Nwangwu was successfully hiding an injury from the Vikings, but the Saints caught it?