It looked like he did tweak it at the time, but then walked it off a little later in the match. It didn't seem like a major injury seeing as he finished the match fairly comfortably, even if it requires a couple of weeks rest, as long as he's back competing in the ring for the TLC PPV, it should be okay. Hopefully it doesn't come down to that though.
No he didn't. It was earlier. Kane was on the ground and Punk went in the corner, grabbed the ropes and squatted down (no not to poop) and he was working his leg. He rolled out of the ring seemingly not caring that Kane was following who seemed to back off for a second. The rest of the match Punk had a slight limp.