This has probably already been talked about, but let's discuss the severed leg. How did that happen? It wouldn't just snap off. Some people think Carol may have done it or even Sam but that seems unlikely. Sam wasn't armed with anything like that and Carol was with Rick (right?) but the main topic about this discussion is how the hell did these two freaking get so far? It has been over a year, how many is unspecified. These two seem completely incompetent due to their soft upbeat personalities and them being carefree. It feels like bad writing. I know I'm nitpicking at this but it was so obvious they weren't going to make it and how exactly Ana was going to die - typically being killed off because of their injured leg - even finding the leg severed has become a cliche. But my question is this, how did these two get so far? Did they have a strong group before or was it all down to dumb luck?
It's safe to assume now that Ana was killed by the Terminus Hunters.
Sam was slaughtered for food in Terminus, and "tainted meat" was a big thing for the Hunters in the comic. They would have severed her "tainted" leg and left her to die. Wether it had a purpose or for their own sadistic joy, we'll never know.
The only hole for me is how that could have happened without alerting Rick or Carol.